Add travis.yml

Test against:
  - python2.7 and and python3.4
  - and django 1.6 and 1.7
Use mock third party library to be compatible with python2.7
Update test to check for new fields
Update dj-datatbase-url version in requirement
Simplify test_handle_modeladmin
Add README.md
Replace MockRequest with mock.Mock
Merge pull request #4 from incuna/add-travis

Add travis