Add django master to build matrix. Closes #2075.
Merge pull request #2082 from tomchristie/add-django-master-to-build-matrix

Add Django `master` to build matrix.
Fix runtests examples

Correctly rename runtests examples to work with current runtests.py file.
Merge pull request #2083 from jpadilla/patch-1

Fix runtests examples
Remove class='form-control' for file inputs. Closes #2065.
Merge branch 'master' of https://github.com/tomchristie/django-rest-framework
Docs for advanced default argument usage. Closes #1945
Note removal of 'save_object' and fail loudly if it exists
Only pass instance to form for PUT and PATCH. Closes #2073.
Add comment ref #2089
Fix byte decode error rendering 'display_name' with OPTIONS. Closes #2084
Note on 3.0 beta
List serializer no explicitly renders as 'not supported for HTML input'
Use the new build env on Travis

faster vms, more ram, more cpu, better vm boot times

official docs coming soon
Merge pull request #2090 from joshk/patch-1

Use the new build env on Travis
Allow blank choices to render. Closes #2071.
Merge branch 'master' of https://github.com/tomchristie/django-rest-framework
Use translatable error strings. Refs #2063.
Apply defaults and requiredness to unique_together fields. Closes #2092.
Further notes in 3.0 announcement