Fix #196: Revise awards JSON feed format

[lmorchard]

Tweaks to JSON feeds to make them hopefully more useful by code targeted at the OBI backpack displayer API

• Awards JSON feed format now looks more like the OpenBadges Backpack
  Displayer format.
  • JSON object with 'badges' property, listing award assertions
  • See also: https://github.com/mozilla/openbadges/wiki/Displayer-API
• Recent badges JSON feed lists BadgeObjects under 'badges' property
• Test updates

[willkg]

Funky! I had no idea you could do that. I have countless places where that would have made life a lot easier.

[willkg]

This is failing with this:

======================================================================

ERROR: test_award_json_feeds (badger.tests.test_feeds.BadgerFeedsTest)

----------------------------------------------------------------------

Traceback (most recent call last):

File "/home/travis/build/mozilla/django-badger/badger/tests/test_feeds.py", line 134, in test_award_json_feeds

b1.get_absolute_url(format='json'))

File "/home/travis/virtualenv/python2.6/lib/python2.6/site-packages/django/utils/functional.py", line 11, in _curried

return _curried_func(*(args+moreargs), **dict(kwargs, **morekwargs))

File "/home/travis/virtualenv/python2.6/lib/python2.6/site-packages/django/db/models/base.py", line 883, in get_absolute_url

return settings.ABSOLUTE_URL_OVERRIDES.get('%s.%s' % (opts.app_label, opts.module_name), func)(self, *args, **kwargs)

TypeError: get_absolute_url() got an unexpected keyword argument 'format'

-------------------- >> begin captured stdout << ---------------------

I think that format thing is in the other PR. Is that right?