Expand travis.yml build platforms

.travis.yml

@@ -1,34 +1,28 @@
-os:
-  - linux
-
 language: node_js
 
-addons:
-  apt:
-    sources:
-    - ubuntu-toolchain-r-test
-    packages:
-    - g++-4.8
-
 node_js:
   - "6"
   - "8"
   - "10"
   - "12"
 
-install:
-  - export CXX=g++-4.8
-  - $CXX --version
-  - npm i
+os:
+  - linux
+  - mac
+  - windows
 
-notifications:
-  email:
-    on_success: never
-    on_failure: change
+env:
+  global:
+    - npm_config_jobs=max
 
 git:
   depth: 10
 
 branches:
   only:
     - master
+
+notifications:
+  email:
+    on_success: never
+    on_failure: change