do not run test/credentials.coffee as a test
HTTP 429 errors now only emit a warning
enables test watching for better coding experience
improves testing assertions (eg: assert x==y => assert.equal x,y)
Modularize private _handle_http_429
2.0.0
Merge pull request #28 from Clever/INFRA-272-better-rate-limit-handling

[INFRA-272] better rate limit handling