diff --git a/package-lock.json b/package-lock.json
index 382934c..55cc177 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -32,6 +32,12 @@
         }
       }
     },
+    "@tootallnate/once": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/@tootallnate/once/-/once-1.1.2.tgz",
+      "integrity": "sha512-RbzJvlNzmRq5c3O09UipeuXno4tA1FE6ikOjxZK0tuxVv3412l64l5t1W5pj4+rJq9vpkm/kwiR07aZXnsKPxw==",
+      "dev": true
+    },
     "abab": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/abab/-/abab-2.0.0.tgz",
@@ -86,12 +92,23 @@
       "dev": true
     },
     "agent-base": {
-      "version": "4.3.0",
-      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-4.3.0.tgz",
-      "integrity": "sha512-salcGninV0nPrwpGNn4VTXBb1SOuXQBiqbrNXoeizJsHrsL6ERFM2Ne3JUSBWRE6aeNJI2ROP/WEEIDUiDe3cg==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-6.0.1.tgz",
+      "integrity": "sha512-01q25QQDwLSsyfhrKbn8yuur+JNw0H+0Y4JiGIKd3z9aYk/w/2kxD/Upc+t2ZBBSUNff50VjPsSW2YxM8QYKVg==",
       "dev": true,
       "requires": {
-        "es6-promisify": "^5.0.0"
+        "debug": "4"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "4.1.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
+          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "dev": true,
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        }
       }
     },
     "ajv": {
@@ -1177,16 +1194,16 @@
       "dev": true
     },
     "codecov": {
-      "version": "3.5.0",
-      "resolved": "https://registry.npmjs.org/codecov/-/codecov-3.5.0.tgz",
-      "integrity": "sha512-/OsWOfIHaQIr7aeZ4pY0UC1PZT6kimoKFOFYFNb6wxo3iw12nRrh+mNGH72rnXxNsq6SGfesVPizm/6Q3XqcFQ==",
+      "version": "3.7.1",
+      "resolved": "https://registry.npmjs.org/codecov/-/codecov-3.7.1.tgz",
+      "integrity": "sha512-JHWxyPTkMLLJn9SmKJnwAnvY09kg2Os2+Ux+GG7LwZ9g8gzDDISpIN5wAsH1UBaafA/yGcd3KofMaorE8qd6Lw==",
       "dev": true,
       "requires": {
-        "argv": "^0.0.2",
-        "ignore-walk": "^3.0.1",
-        "js-yaml": "^3.13.1",
-        "teeny-request": "^3.11.3",
-        "urlgrey": "^0.4.4"
+        "argv": "0.0.2",
+        "ignore-walk": "3.0.3",
+        "js-yaml": "3.13.1",
+        "teeny-request": "6.0.1",
+        "urlgrey": "0.4.4"
       },
       "dependencies": {
         "js-yaml": {
@@ -1600,21 +1617,6 @@
         "is-symbol": "^1.0.2"
       }
     },
-    "es6-promise": {
-      "version": "4.2.8",
-      "resolved": "https://registry.npmjs.org/es6-promise/-/es6-promise-4.2.8.tgz",
-      "integrity": "sha512-HJDGx5daxeIvxdBxvG2cb9g4tEvwIk3i8+nhX0yGrYmZUzbkdg8QbDevheDB8gd0//uPj4c1EQua8Q+MViT0/w==",
-      "dev": true
-    },
-    "es6-promisify": {
-      "version": "5.0.0",
-      "resolved": "https://registry.npmjs.org/es6-promisify/-/es6-promisify-5.0.0.tgz",
-      "integrity": "sha1-UQnWLz5W6pZ8S2NQWu8IKRyKUgM=",
-      "dev": true,
-      "requires": {
-        "es6-promise": "^4.0.3"
-      }
-    },
     "escape-string-regexp": {
       "version": "1.0.5",
       "resolved": "https://registry.npmjs.org/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz",
@@ -2986,6 +2988,28 @@
         "whatwg-encoding": "^1.0.1"
       }
     },
+    "http-proxy-agent": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/http-proxy-agent/-/http-proxy-agent-4.0.1.tgz",
+      "integrity": "sha512-k0zdNgqWTGA6aeIRVpvfVob4fL52dTfaehylg0Y4UvSySvOq/Y+BOyPrgpUrA7HylqvU8vIZGsRuXmspskV0Tg==",
+      "dev": true,
+      "requires": {
+        "@tootallnate/once": "1",
+        "agent-base": "6",
+        "debug": "4"
+      },
+      "dependencies": {
+        "debug": {
+          "version": "4.1.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
+          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "dev": true,
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        }
+      }
+    },
     "http-signature": {
       "version": "1.2.0",
       "resolved": "https://registry.npmjs.org/http-signature/-/http-signature-1.2.0.tgz",
@@ -2998,13 +3022,30 @@
       }
     },
     "https-proxy-agent": {
-      "version": "2.2.2",
-      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-2.2.2.tgz",
-      "integrity": "sha512-c8Ndjc9Bkpfx/vCJueCPy0jlP4ccCCSNDp8xwCZzPjKJUm+B+u9WX2x98Qx4n1PiMNTWo3D7KK5ifNV/yJyRzg==",
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/https-proxy-agent/-/https-proxy-agent-4.0.0.tgz",
+      "integrity": "sha512-zoDhWrkR3of1l9QAL8/scJZyLu8j/gBkcwcaQOZh7Gyh/+uJQzGVETdgT30akuwkpL8HTRfssqI3BZuV18teDg==",
       "dev": true,
       "requires": {
-        "agent-base": "^4.3.0",
-        "debug": "^3.1.0"
+        "agent-base": "5",
+        "debug": "4"
+      },
+      "dependencies": {
+        "agent-base": {
+          "version": "5.1.1",
+          "resolved": "https://registry.npmjs.org/agent-base/-/agent-base-5.1.1.tgz",
+          "integrity": "sha512-TMeqbNl2fMW0nMjTEPOwe3J/PRFP4vqeoNuQMG0HlMrtm5QxKqdvAkZ1pRBQ/ulIyDD5Yq0nJ7YbdD8ey0TO3g==",
+          "dev": true
+        },
+        "debug": {
+          "version": "4.1.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
+          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "dev": true,
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        }
       }
     },
     "iconv-lite": {
@@ -3022,9 +3063,9 @@
       "dev": true
     },
     "ignore-walk": {
-      "version": "3.0.1",
-      "resolved": "https://registry.npmjs.org/ignore-walk/-/ignore-walk-3.0.1.tgz",
-      "integrity": "sha512-DTVlMx3IYPe0/JJcYP7Gxg7ttZZu3IInhuEhbchuqneY9wWe5Ojy2mXLBaQFUQmo0AW2r3qG7m1mg86js+gnlQ==",
+      "version": "3.0.3",
+      "resolved": "https://registry.npmjs.org/ignore-walk/-/ignore-walk-3.0.3.tgz",
+      "integrity": "sha512-m7o6xuOaT1aqheYHKf8W6J5pYH85ZI9w077erOzLje3JsB1gkafkAhHHY19dqjulgIZHFm32Cp5uNZgcQqdJKw==",
       "dev": true,
       "requires": {
         "minimatch": "^3.0.4"
@@ -5826,6 +5867,15 @@
       "integrity": "sha1-NbCYdbT/SfJqd35QmzCQoyJr8ks=",
       "dev": true
     },
+    "stream-events": {
+      "version": "1.0.5",
+      "resolved": "https://registry.npmjs.org/stream-events/-/stream-events-1.0.5.tgz",
+      "integrity": "sha512-E1GUzBSgvct8Jsb3v2X15pjzN1tYebtbLaMg+eBOUOAxgbLoSbT2NS91ckc5lJD1KfLjId+jXJRgo0qnV5Nerg==",
+      "dev": true,
+      "requires": {
+        "stubs": "^3.0.0"
+      }
+    },
     "string-length": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/string-length/-/string-length-2.0.0.tgz",
@@ -5882,6 +5932,12 @@
       "integrity": "sha1-PFMZQukIwml8DsNEhYwobHygpgo=",
       "dev": true
     },
+    "stubs": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/stubs/-/stubs-3.0.0.tgz",
+      "integrity": "sha1-6NK6H6nJBXAwPAMLaQD31fiavls=",
+      "dev": true
+    },
     "supports-color": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-2.0.0.tgz",
@@ -5909,13 +5965,15 @@
       }
     },
     "teeny-request": {
-      "version": "3.11.3",
-      "resolved": "https://registry.npmjs.org/teeny-request/-/teeny-request-3.11.3.tgz",
-      "integrity": "sha512-CKncqSF7sH6p4rzCgkb/z/Pcos5efl0DmolzvlqRQUNcpRIruOhY9+T1FsIlyEbfWd7MsFpodROOwHYh2BaXzw==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/teeny-request/-/teeny-request-6.0.1.tgz",
+      "integrity": "sha512-TAK0c9a00ELOqLrZ49cFxvPVogMUFaWY8dUsQc/0CuQPGF+BOxOQzXfE413BAk2kLomwNplvdtMpeaeGWmoc2g==",
       "dev": true,
       "requires": {
-        "https-proxy-agent": "^2.2.1",
+        "http-proxy-agent": "^4.0.0",
+        "https-proxy-agent": "^4.0.0",
         "node-fetch": "^2.2.0",
+        "stream-events": "^1.0.5",
         "uuid": "^3.3.2"
       },
       "dependencies": {
diff --git a/yarn.lock b/yarn.lock
index d65a7a3..1a5c083 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -16,6 +16,10 @@
     esutils "^2.0.2"
     js-tokens "^3.0.0"
 
+"@tootallnate/once@1":
+  version "1.1.2"
+  resolved "https://registry.yarnpkg.com/@tootallnate/once/-/once-1.1.2.tgz#ccb91445360179a04e7fe6aff78c00ffc1eeaf82"
+
 abab@^1.0.4:
   version "1.0.4"
   resolved "https://registry.yarnpkg.com/abab/-/abab-1.0.4.tgz#5faad9c2c07f60dd76770f71cf025b62a63cfd4e"
@@ -44,11 +48,15 @@ acorn@^5.0.0, acorn@^5.3.0, acorn@^5.5.0:
   version "5.5.3"
   resolved "https://registry.yarnpkg.com/acorn/-/acorn-5.5.3.tgz#f473dd47e0277a08e28e9bec5aeeb04751f0b8c9"
 
-agent-base@^4.3.0:
-  version "4.3.0"
-  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-4.3.0.tgz#8165f01c436009bccad0b1d122f05ed770efc6ee"
+agent-base@5:
+  version "5.1.1"
+  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-5.1.1.tgz#e8fb3f242959db44d63be665db7a8e739537a32c"
+
+agent-base@6:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/agent-base/-/agent-base-6.0.1.tgz#808007e4e5867decb0ab6ab2f928fbdb5a596db4"
   dependencies:
-    es6-promisify "^5.0.0"
+    debug "4"
 
 ajv-keywords@^2.1.0:
   version "2.1.1"
@@ -115,7 +123,7 @@ argparse@^1.0.7:
   dependencies:
     sprintf-js "~1.0.2"
 
-argv@^0.0.2:
+argv@0.0.2:
   version "0.0.2"
   resolved "https://registry.yarnpkg.com/argv/-/argv-0.0.2.tgz#ecbd16f8949b157183711b1bda334f37840185ab"
 
@@ -542,14 +550,14 @@ code-point-at@^1.0.0:
   resolved "https://registry.yarnpkg.com/code-point-at/-/code-point-at-1.1.0.tgz#0d070b4d043a5bea33a2f1a40e2edb3d9a4ccf77"
 
 codecov@^3.5.0:
-  version "3.5.0"
-  resolved "https://registry.yarnpkg.com/codecov/-/codecov-3.5.0.tgz#3d0748932f9cb41e1ad7f21fa346ef1b2b1bed47"
+  version "3.7.1"
+  resolved "https://registry.yarnpkg.com/codecov/-/codecov-3.7.1.tgz#434cb8d55f18ef01672e5739d3d266696bebc202"
   dependencies:
-    argv "^0.0.2"
-    ignore-walk "^3.0.1"
-    js-yaml "^3.13.1"
-    teeny-request "^3.11.3"
-    urlgrey "^0.4.4"
+    argv "0.0.2"
+    ignore-walk "3.0.3"
+    js-yaml "3.13.1"
+    teeny-request "6.0.1"
+    urlgrey "0.4.4"
 
 collection-visit@^1.0.0:
   version "1.0.0"
@@ -663,6 +671,12 @@ data-urls@^1.0.0:
     whatwg-mimetype "^2.0.0"
     whatwg-url "^6.4.0"
 
+debug@4:
+  version "4.1.1"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-4.1.1.tgz#3b72260255109c6b589cee050f1d516139664791"
+  dependencies:
+    ms "^2.1.1"
+
 debug@^2.1.2, debug@^2.2.0, debug@^2.3.3, debug@^2.6.8, debug@^2.6.9:
   version "2.6.9"
   resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
@@ -830,16 +844,6 @@ es-to-primitive@^1.1.1:
     is-date-object "^1.0.1"
     is-symbol "^1.0.1"
 
-es6-promise@^4.0.3:
-  version "4.2.8"
-  resolved "https://registry.yarnpkg.com/es6-promise/-/es6-promise-4.2.8.tgz#4eb21594c972bc40553d276e510539143db53e0a"
-
-es6-promisify@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.yarnpkg.com/es6-promisify/-/es6-promisify-5.0.0.tgz#5109d62f3e56ea967c4b63505aef08291c8a5203"
-  dependencies:
-    es6-promise "^4.0.3"
-
 escape-string-regexp@^1.0.2, escape-string-regexp@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
@@ -1420,6 +1424,14 @@ html-encoding-sniffer@^1.0.2:
   dependencies:
     whatwg-encoding "^1.0.1"
 
+http-proxy-agent@^4.0.0:
+  version "4.0.1"
+  resolved "https://registry.yarnpkg.com/http-proxy-agent/-/http-proxy-agent-4.0.1.tgz#8a8c8ef7f5932ccf953c296ca8291b95aa74aa3a"
+  dependencies:
+    "@tootallnate/once" "1"
+    agent-base "6"
+    debug "4"
+
 http-signature@~1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/http-signature/-/http-signature-1.2.0.tgz#9aecd925114772f3d95b65a60abb8f7c18fbace1"
@@ -1428,12 +1440,12 @@ http-signature@~1.2.0:
     jsprim "^1.2.2"
     sshpk "^1.7.0"
 
-https-proxy-agent@^2.2.1:
-  version "2.2.2"
-  resolved "https://registry.yarnpkg.com/https-proxy-agent/-/https-proxy-agent-2.2.2.tgz#271ea8e90f836ac9f119daccd39c19ff7dfb0793"
+https-proxy-agent@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/https-proxy-agent/-/https-proxy-agent-4.0.0.tgz#702b71fb5520a132a66de1f67541d9e62154d82b"
   dependencies:
-    agent-base "^4.3.0"
-    debug "^3.1.0"
+    agent-base "5"
+    debug "4"
 
 iconv-lite@0.4.19:
   version "0.4.19"
@@ -1445,9 +1457,9 @@ iconv-lite@^0.4.17, iconv-lite@^0.4.4, iconv-lite@~0.4.13:
   dependencies:
     safer-buffer ">= 2.1.2 < 3"
 
-ignore-walk@^3.0.1:
-  version "3.0.1"
-  resolved "https://registry.yarnpkg.com/ignore-walk/-/ignore-walk-3.0.1.tgz#a83e62e7d272ac0e3b551aaa82831a19b69f82f8"
+ignore-walk@3.0.3, ignore-walk@^3.0.1:
+  version "3.0.3"
+  resolved "https://registry.yarnpkg.com/ignore-walk/-/ignore-walk-3.0.3.tgz#017e2447184bfeade7c238e4aefdd1e8f95b1e37"
   dependencies:
     minimatch "^3.0.4"
 
@@ -2083,20 +2095,13 @@ js-tokens@^3.0.0, js-tokens@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/js-tokens/-/js-tokens-3.0.2.tgz#9866df395102130e38f7f996bceb65443209c25b"
 
-js-yaml@^3.13.1:
+js-yaml@3.13.1, js-yaml@^3.7.0, js-yaml@^3.9.1:
   version "3.13.1"
   resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.13.1.tgz#aff151b30bfdfa8e49e05da22e7415e9dfa37847"
   dependencies:
     argparse "^1.0.7"
     esprima "^4.0.0"
 
-js-yaml@^3.7.0, js-yaml@^3.9.1:
-  version "3.11.0"
-  resolved "https://registry.yarnpkg.com/js-yaml/-/js-yaml-3.11.0.tgz#597c1a8bd57152f26d622ce4117851a51f5ebaef"
-  dependencies:
-    argparse "^1.0.7"
-    esprima "^4.0.0"
-
 jsbn@~0.1.0:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/jsbn/-/jsbn-0.1.1.tgz#a5e654c2e5a2deb5f201d96cefbca80c0ef2f513"
@@ -2407,6 +2412,10 @@ ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
 
+ms@^2.1.1:
+  version "2.1.2"
+  resolved "https://registry.yarnpkg.com/ms/-/ms-2.1.2.tgz#d09d1f357b443f493382a8eb3ccd183872ae6009"
+
 mute-stream@0.0.7:
   version "0.0.7"
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"
@@ -3243,6 +3252,12 @@ stealthy-require@^1.1.0:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/stealthy-require/-/stealthy-require-1.1.1.tgz#35b09875b4ff49f26a777e509b3090a3226bf24b"
 
+stream-events@^1.0.5:
+  version "1.0.5"
+  resolved "https://registry.yarnpkg.com/stream-events/-/stream-events-1.0.5.tgz#bbc898ec4df33a4902d892333d47da9bf1c406d5"
+  dependencies:
+    stubs "^3.0.0"
+
 string-length@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/string-length/-/string-length-2.0.0.tgz#d40dbb686a3ace960c1cffca562bf2c45f8363ed"
@@ -3301,6 +3316,10 @@ strip-json-comments@~2.0.1:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/strip-json-comments/-/strip-json-comments-2.0.1.tgz#3c531942e908c2697c0ec344858c286c7ca0a60a"
 
+stubs@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/stubs/-/stubs-3.0.0.tgz#e8d2ba1fa9c90570303c030b6900f7d5f89abe5b"
+
 supports-color@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/supports-color/-/supports-color-2.0.0.tgz#535d045ce6b6363fa40117084629995e9df324c7"
@@ -3344,12 +3363,14 @@ tar@^4:
     safe-buffer "^5.1.2"
     yallist "^3.0.2"
 
-teeny-request@^3.11.3:
-  version "3.11.3"
-  resolved "https://registry.yarnpkg.com/teeny-request/-/teeny-request-3.11.3.tgz#335c629f7645e5d6599362df2f3230c4cbc23a55"
+teeny-request@6.0.1:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/teeny-request/-/teeny-request-6.0.1.tgz#9b1f512cef152945827ba7e34f62523a4ce2c5b0"
   dependencies:
-    https-proxy-agent "^2.2.1"
+    http-proxy-agent "^4.0.0"
+    https-proxy-agent "^4.0.0"
     node-fetch "^2.2.0"
+    stream-events "^1.0.5"
     uuid "^3.3.2"
 
 test-exclude@^4.2.1:
@@ -3473,7 +3494,7 @@ urix@^0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/urix/-/urix-0.1.0.tgz#da937f7a62e21fec1fd18d49b35c2935067a6c72"
 
-urlgrey@^0.4.4:
+urlgrey@0.4.4:
   version "0.4.4"
   resolved "https://registry.yarnpkg.com/urlgrey/-/urlgrey-0.4.4.tgz#892fe95960805e85519f1cd4389f2cb4cbb7652f"