Make the project self-contained

Also make URL patterns reference views directly.
Have Travis use proper settings
Fix imports
Drop test discovery
Reorganize tests and dependencies
Iron some Python 3 wrinkles
Use unicode literals
Bump django-payments
One more literal
Bump django-payments
Bump django-payments
Rename shop to saleor, Python 3 compatibility
Bump requirements to use prices 0.5
Merge pull request #71 from mirumee/self-contained-project

Make the project self-contained