Fix on Python 3, don't allow failure in Travis

- cStringIO.StringIO vs io.StringIO
- urlparse.urlparse vs urllib.urlparse
- iterools.izip vs zip
- Remove some unused code with Python 3 problems
- add some `from __future__ import unicode_literals`
- local imports ie `from .views import foo`
- upversion python-batcher, support for Python 3
- Factor out `json.loads` into test_utils lib

https://www.pivotaltracker.com/story/show/73971230