test: [karma] use karma phantomjs runner

- tests refactored as bdd instead of tdd
- removed test/browser bootstraps
- add karma-runner
travis: only run on node 0.10
tests: add sauce support to karma
tests: [sauce] error in setup
travis: use karma to start connect
test: [sauce] use karma@canary to prevent timeouts
docs: add sauce badge to readme [ci skip]
Merge branch 'feature/karma'