Drop tick() from LoopInterface

[jsor]

References: #52 (comment), async-interop/event-loop#9

For the tests, i've added a helper function to TestCase.

Closes#52

[clue]

Yes 👍

This has been discussed plenty of times already and we have yet to come up with a use case that actually needs the tick() method. Removing this makes perfect sense, it avoids plenty of issues related to it, reduces implementation complexity and perceived external complexity (smaller public API).

[jsor]

I'd like to hear from @WyriHaximus about this because IIRC he's using tick() in a few of his libs.

[WyriHaximus]

@jsor Glad to see this horrible hack go 👍 . I use it in one lib, but don't really recommend it, and really would prefer not to use and have it at all.

[jsor]

Since this a BC break, i'd like to have also @cboden's approval here.