Don't silently swallow JSON errors.
Add a dependency on six.
Initial syntax fixes to get the test suite running.
Fixed imports to be 2/3 compatible.
b64encode returns bytes, so fix the Authorization header accordingly.

I'm not 100% sure this is correct: if usernames can be non-ASCII this'll
break. If so, the Librato docs don't say what to do; b64 needs to operate on
bytes, and it's unclear how to encode the username properly. I'd assume
UTF-8, but Latin-1 would be reasonable as well.
dict.has_key -> key in dict.
Fixed assumptions about dict ordering.

The better fix might have been to update the assertions themselves to
not make assumptions about ordering, but using a odict was faster. If
this needs to support Py2.6 it'd need to be refactored further.
Remove __version__ import from setup.py

If you import __version__, it's triggers the six import in librato/__init__,
which fails because setup.py hasn't had a chance to install dependencies yet.
Removed the now-no-longer-needed ez_setup bootstrap from setup.py
Added a tox.ini to ensure this still works on Py2.7 (it does).
Update Travis to test against Python 3 also.
Correctly decode JSON responses based on content-type.

(Also clean up a dangling PDB, oops.)
Merge pull request #19 from jacobian/py3

Python 3 support