Clean up repository

* remove django db (should not be versionned)
* remove *.pyc (python bytecode)
* add .gitignore file to ignore previously mentionned files
* sqlite db filename should contain the sqlite extension (more explicit)
Activate admin interface
Clean up repository from python bytecode
Add core views
Fix conflicts
Add only necessary requirements
Ignore backup files
Add a basic README
Fix merge mistake
Update models
Fix settings
Clean up unused files
Add default ViewSet for models
Flake8 cleanup
Merge pull request #5 from jmaupetit/develop

Perform some cleanup