Deal with chronos jobs that have spaces in the name

[solarkennedy]

This patch correctly will quote the URL when we interact with the chronos api, so it properly deals with characters like spaces in chronos job names (which are perfectly valid chronos job names).

This is analogous to how the actual web interface works when you click the new job button.

[mrtyler]

shipit

[solarkennedy]

I don't understand why travis has a green checkmark for the failing test commit. That sha definitly fails the itests and it is not using urlencoded urls:

chronos-python (b4b0d31...) $ make itests
...
Fetch: DELETE /scheduler/job/test chronos job with spaces
http://0.0.0.0:32873/scheduler/job/test chronos job with spaces
status: 400
    And we should be able to delete it                                  # steps/chronos_steps.py:65 0.003s
    And we should not be able to see it when we list jobs               # steps/chronos_steps.py:70
Fetch: GET /scheduler/jobs
http://0.0.0.0:32873/scheduler/jobs
    And we should not be able to see it when we list jobs               # steps/chronos_steps.py:70 0.023s
      Traceback (most recent call last):
        File "/nail/home/kwa/Projects/chronos-python/.tox/itests/local/lib/python2.7/site-packages/behave/model.py", line 1456, in run
          match.run(runner.context)
        File "/nail/home/kwa/Projects/chronos-python/.tox/itests/local/lib/python2.7/site-packages/behave/model.py", line 1903, in run
          self.func(context, *args, **kwargs)
        File "steps/chronos_steps.py", line 74, in not_see_job_with_spaces
          assert "test chronos job with spaces" not in job_names
      AssertionError

      Captured logging:
      ERROR:chronos:Response not valid json: Error: 400

In the output it just has a git checkout of "HEAD", so that run in travis doesn't reflect the actual failing test.

In other words, this bug is real and the second commit really fixes it.

I'll merge this into our own fork and do an internal release to unblock us.