Removing SignedJwtAssertionCredentials.

[nathanielmanistaatgoogle]

This is #399 with tests/test__pycrypto_crypt.py changed to use unittest2.

[dhermes]

LGTM, though I meant to update the s to json_str change actually be json_data (based on #396 or #397)

[nathanielmanistaatgoogle]

I can change json_str to json_data.

Any idea why the tests haven't yet kicked off for this?

[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request) and all commit authors, but as best as we can tell these commits were authored by someone else. If that's the case, please add them to this pull request and have them confirm that they're okay with these commits being contributed to Google. If we're mistaken and you did author these commits, just reply here to confirm.

[nathanielmanistaatgoogle]

@googlebot you're being silly and failing to recognize an authored-by-@dhermes-committed-by-@nathanielmanistaatgoogle commit as legitimate to merge.

[dhermes]

1. ISTM the google org gets rate limited (also having 8 Travis envs probably doesn't help)
2. I've had the CLA check fail like this before. I think it's a corner case the server isn't implemented to handle?

[nathanielmanistaatgoogle]

Changed json_str to json_data in oauth2client/client.py; please take another quick look.

Any way to poke Travis to make it notice that a different commit has been pushed? I cancelled the test run of 81da3192423237b6.

[dhermes]

You've gotta figure out what the rate limit is. Need to check with whoever owns the org

[dhermes]

Still LGTM