add functional tests

How the test works:
  A simple example app is created, multiple experiment dimensions is configured like here (https://git.corp.yahoo.com/dgomez/search-dimensions-experiment_example). Then the test will create an instance of app.js, shake resources, then call markup-test.render (https://github.com/yahoo/mojito-markup-test) with context set to different dimension values, as listed below:
   experiment_example: VIEW
   experiment_example: CSS
   experiment_example: ADDON
   experiment_example: CONTROLLER
   experiment_example: BINDER
returned markup will tell whether corresponding dimension is working, by comparing with a expected html file in test fixtures, thus when further changes break things the tests will fail.

TODO:
CONFIG is working by testing manually but is trickier to add to test cases since it'll inter affect other tests, need to come up with ways to test that.
Please don't commit all these commented lines, unless you have a good reason to, in which case explain it in a comment :smile: