Run mocha tests on Travis

Author: jscheid

.travis.yml

@@ -17,3 +17,4 @@ before_script:
   - sh -e /etc/init.d/xvfb start
 script:
   - ./node_modules/karma/bin/karma start --single-run --browsers Firefox
+  - ./node_modules/mocha/bin/mocha test/test-webpack.js