Update to use latest tester and helpers.
Merge pull request #19 from Brightspace/nstonehouse/refactoring/tester-and-helpers

Update to use latest tester and helpers.
Updating LESS variable names and mixins for consistency.
Merge pull request #20 from Brightspace/dbatiste/consistency

Updating LESS variable names and mixins for consistency.
Merge branch 'master' of https://github.com/Desire2Learn-Valence/valence-ui-button into upgrade-gradient-ie9fix

Conflicts:
	package.json