Add 3.0 announcement
Support Django's core ValidationError for backwards compat. Refs #2145.
More descriptive docstring on ModelSerializer
Minor validtors tweak
Minor 3.0 announcment tweaks
Add missing 'validators.py' link. Closes #2166.
Change allow_none to allow_null
Merge pull request #2167 from jpadilla/patch-1

Change allow_none to allow_null in 3.0 announcement
Fix requirements. Closes #2170.
Merge branch 'master' of github.com:tomchristie/django-rest-framework