Cli test

This Pull Request  builds up on the original request  for a test suite for CLI commands.
Also has a small fix for argument mismatch in haas/cli.py.
These should be instance variables, not static class variables - as it stands it looks to me like if you were to use e.g. `do_put` and `do_get` in the same test, it would do `GET` requests for both, because you're setting that one last.