* Get rid of runtests.py
 * Moved test code  from rest_framework/tests and rest_framework/runtests to tests
 * Invoke py.test from setup.py
 * Invoke py.test from Travis
 * Invoke py.test from tox
 * Changed setUpClass to be just plain setUp in test_permissions.py
 * Updated contribution guideline to show how to invoke py.test

clarified which urls.py to edit

Display the media type of the API response on the browsable API

Update Travis to test Django 1.6.2

TestCases and POST/PUT'ing serialized data that contains `None`

handle zero and negative available_requests

We should be testing the latest version of Django 1.6 as we're doing in the other 1.x releases.

Minor docs example fix

Dates are smaller when they happen before.

include djangorestframework-httpsignature in the docs

fix(docs): fix code indentation in serializers.md

It fixes the indentation of `restore_object()` in the section "Specifying which fields should be write-only" serializers documentation.

Refactor UpdateModelMixin.update

Reduce nesting, return early in error cases.

Update throttling.md

Added comma to make DEFAULT_THROTTLE_CLASSES a tuple in example, for copy&paste to work nicely.

Minor typos fixed in api-guide/testing.md (request -> response).

Add myself into credits.md

update regex for matching URLs, fixes issue #1386

Fixed Testing docs section

Closes #1210.