Allow relative condition module names

[m-mujica]

Closes #33

[m-mujica]

@matthewp I moved the tests from the steal branch here, also since I'm not a fan of the makeIframe thing I found qunit-composite it's a little bit noisy but works fine

https://travis-ci.org/stealjs/steal-conditional/builds/208778047#L355-L369

[m-mujica]

I ran steal-tools tests against this branch, looking good https://github.com/stealjs/steal-tools/pull/621

[matthewp]

Ah, composite looks quite nice!

[matthewp]

Ready to release.