Testing improvements
Cleanup attributesFor
Merge pull request #313 from GrahamCampbell/2.1-tests

Testing Improvements
Merge pull request #315 from GrahamCampbell/2.1-cleanup

[2.1] Cleanup attributesFor
Merge remote-tracking branch 'origin/2.1'
Merge remote-tracking branch 'origin/master' into experimental

Conflicts:
	src/FactoryMuffin.php
Cleanup, and rename attributesFor to generate