Testing strategy

[juliankrispel]

I've got my own opinions here, but I might as well open this up for discussion, I'd like to here from folks, what's your opinion on testing draft js functionality, how do you approach testing and why?

cc @freedomlang @nikgraf @Rosey ❤️

[freedomlang]

@juliankrispel Not familiar in test. How about karma, mocha, chai(for BDD Assertion Library), enzyme(for React ), sinon(for test double) and Istanbul(for code coverage)?