chartbeat: port tests, update mocha
hellobar: port tests
Merge pull request #297 from segmentio/test/hellobar

hellobar: port tests
hittail: port tests
Merge pull request #299 from segmentio/test/hittail

hittail: port tests
Merge pull request #286 from segmentio/test/chartbeat

chartbeat: port tests, update mocha
olark: add groupId, resolves #293