feat(travis): Add gitter hooks

Author: pilsy

.travis.yml

@@ -13,3 +13,11 @@ before_install:
 cache:
   directories:
     - node_modules
+
+notifications:
+  webhooks:
+    urls:
+      - https://webhooks.gitter.im/e/515d4eb7d44adbed410b
+    on_success: change  # options: [always|never|change] default: always
+    on_failure: always  # options: [always|never|change] default: always
+    on_start: false     # default: false