Merge remote-tracking branch 'upstream/master' into writable-nested-modelserializer
Merge remote-tracking branch 'upstream/master' into writable-nested-modelserializer
Merge pull request #931 from mindlace-mp/writable-nested-modelserializer

Merged master into writable-nested-modelserializer.
Merge branch 'writable-nested-modelserializer' of github.com:tomchristie/django-rest-framework into writable-nested-modelserializer