* Add a volume to store the tox cache on the host. This gives quite some speed boost when running lint_docker and test_docker.
* Only map .tox directory for cache.
* Allow bower install of frontend components as root. Needed for frontend development in docker since everything runs as root in the docker image.
* Improve development workflow in docker
* Use LANG=C.UTF-8 in tox. Fixes installation of libraries with UTF-8 in it's readme.
* Install mysqlclient psycopg2 uvloop after requirements_all.txt again, but with a --no-cache-dir this time. Allows bootstrap_frontend to be executed in a different path like the other scripts.