Add travis config

.travis.yml

+language: node_js
+node_js:
+ - "6.9.0"
+ - "6.0.0"
+script:
+ - npm test
+ - npm run-script lint
+notifications:
+    webhooks:
+        urls:
+            - "https://scalar.vector.im/api/neb/services/hooks/dHJhdmlzLWNpLyU0MEhhbGYtU2hvdCUzQWhhbGYtc2hvdC51ay8lMjFxUE5PblVzTnNaclRvRlpxeEIlM0FoYWxmLXNob3QudWs"
+        on_success: change  # always|never|change
+        on_failure: always
+        on_start: never