BREAKING CHANGE: Remove Node 0.12 support (#524)

Remove Node 0.12 support due to mocha (our tests) dropping support.
Add Node 8, 9 support.

Author: jimthedev

.travis.yml

@@ -9,11 +9,12 @@ branches:
 notifications:
   email: false
 node_js:
+- '9'
+- '8'
 - '7'
 - '6'
 - '5'
 - '4'
-- '0.12'
 before_install:
 - git config --global user.name "TravisCI"
 - git config --global user.email "[email protected]"