Scaffolding: Travis, pre-commit, npm-scripts and test

[maxis1718]

1. Add travis config: .travis.yml
2. Add pre-commit hook, i.e., run jshint before git commit
3. Add scripts of npm, e.g., npm test, npm lint
4. Register a distribution task serve:dist, which can be started by running npm start
5. Register a task mocha to run test using gulp-mocha

[maxis1718]

in the previous build failed:

...
[17:29:56] 'fonts' errored after 37 ms
[17:29:56] Error: Bower components directory does not exist at /home/travis/build/fxxkit/yummy/bower_components
...

according to this solution, let's add bower install in .travis.yml to install bower components