Protractor adapter - hasClass implementation is wrong

[NitayRabi]

When using class list, the adapter uses element.getAttribute('classList') - this does not work.

(https://github.com/wix-incubator/unidriver/blob/master/adapters/protractor/src/index.ts#L117)

Example from DOM -

Implementation can be based on class/className attribute

see https://stackoverflow.com/questions/20268128/how-to-test-if-an-element-has-class-using-protractor

[GabiGrin]

oh bummer, and this adapter is also not being tested with the test suite.
@NitayRabi do you guys wanna help with this? both the fix and connecting the protractor adapter to the test suite?

PS: I do plan to remove it altogether (#49)