Implement unit tests and consistent codestyle, fix syntax issues

[EricHanLiu]

Unit tests using Jest and Selenium, small syntax errors fixed to remove Lint JSHint warnings, codestyle consistency enforced

Ensured compatibility with Travis and fixed build issues

Documented everything in README

[vigliensoni]

@deepio Can you check this pull request?

[deepio]

@EricHanLiu In the beginning, there are a few large commits where you try to fix multiple unrelated things, and then you change a small section later (fixing a fix, of a specific section of another fix). Try to have a cleaner git history because it makes it harder to track what you did during review. Keep your commits small, think about it as if you're limiting a commit to the length of something specific that you may need to 'revert' in the future. And you can also delete a pushed commit, with some restrictions obviously. I'm definitely not asking you to revert all the changes and reorganize them now, that would be a huge waste of time.

• Normally i'd advise against making codestyle fixes, however, in this project, I'd accept it because it is following the linter that was setup by the original author.

• What is the problem according to jshint for these? https://github.com/DDMAL/pixel_wrapper/blob/008f2ea146bd948ed1ecda7ebfaebe21ee4d8aea/source/js/interpolate-animation.js#L34

now is undefined because its commented out here: https://github.com/DDMAL/pixel_wrapper/blob/e0750621228faab217c838114ba5c73f611dec06/source/js/interpolate-animation.js#L11-L22

Maybe they thought now = () => { return performance.now(); }; looked ugly with two semicolons, but if that's the case I would have picked a different code style or (if eslint+jshint supports it) made some minor adjustments to the rules.

[EricHanLiu]

@deepio Yeah the JSHint warning was because there weren't semicolons, so they commented that section out. In general I didn't change the codestyle of what was already written, just tried to fix the JSHint warnings wherever I could (missing semicolons, missing break statement).

Should I add the semicolons there and remove the // jshint ignore on the now()statements

[EricHanLiu]

Will try to move the tests to target a new server, only hosting once the tests are run (remove dependence on Rodan running)

[EricHanLiu]

Okay all the changes have been made, tests all pass now and no longer require the Rodan server to be running. removed the travis environment variables as well

[EricHanLiu]

can I merge this