upgrade doorkeeper gem
include missing controller modules 

since https://github.com/doorkeeper-gem/doorkeeper/commit/36c110748d22a0a9e65da3ea190d2118aee11fed doorkeeper tokens_controller is bare metal.
Update paper_trail and deps.
Merge pull request #151 from astopy/gem-update

Update paper_trail and deps.
Tidy up Dockerfile.
Add start.sh for Docker and use production by default.
Merge pull request #150 from astopy/master

Docker deployment updates
Add DB migration script for production deployment.
Merge pull request #152 from astopy/master

Add DB migration script for production deployment.
Merge pull request #149 from camallen/gem_upgrades

upgrade doorkeeper