Add 3.0.0 beta test
Avoid private api if metadata is exposed
Load sass and uglifier as test deps
Use beta 4
Merge pull request #189 from rails/test-3-0-beta

Testing 3.0 beta on 2.x
Merge branch '2-2-stable'

Conflicts:
	.travis.yml
	sprockets-rails.gemspec
Merge branch 'master' into beta-only

Conflicts:
	.travis.yml