chore(package): update @types/enzyme to version 3.1.18

Closes #33

Author: greenkeeper[bot]

package.json

@@ -11,7 +11,7 @@
     "react-dom": "^15.4.2"
   },
   "devDependencies": {
-    "@types/enzyme": "^2.7.6",
+    "@types/enzyme": "^3.1.18",
     "@types/jest": "^19.2.2",
     "@types/react": "^15.0.0",
     "@types/react-dom": "^0.14.23",