Fix #36; remove mixin
Fix #48; only allow positive thresholds
Fix #41; pass light and colors to notifier
Fix #47; generate notifications with lambdas
Update changelog
Prevent specs from generating invalid thresholds
Merge branch 'gh-36'
Merge branch 'gh-48'
Update changelog
Merge branch 'gh-41'

Conflicts:
	CHANGELOG.md
Use Ruby 1.9 compatible lambda syntax
Merge branch 'gh-47'
Fix formatting in changelog