Add Sauce Labs test support

[domenic]

I just ripped out Testling because it never works. But working cross-browser cloud testing would be nice.

Zuul has this baked in to some extent; need to look into it more.

@kriskowal also had a pretty extensive doc on how to run the Q v2 tests in Sauce Labs, but I'm having trouble finding it now.

[neonstalwart]

https://github.com/theintern/intern also has builtin integration with sauce labs and is easy to get running with selenium locally too.

/cc @csnover @jason0x43

[domenic]

Last I checked it requires AMD.

[csnover]

Yes, for the tests. Not the code.

[domenic]

Yes, that is not acceptable.

[csnover]

whaaaaaaaaaaa? How is it not acceptable to have your test modules for a browser library written in a browser-compatible module format?

[domenic]

My test modules are already written in a browser-compatible module format, and changing that to support the test library's preferences are not an option on the table.

I would like to discontinue this discussion. If you wish to debate why Intern and/or AMD are good, let's do that elsewhere, but please leave this issue thread for actionable issues.