Issue 86

Fixes #86

Adds 2 new commands that will make developer's life easier:
- clean_test_env: in case a unit test fails and the test db is dirty
- drop_test_env: in case the settings table changes and need to rebuild the test env, this allows to drop the old one
This function is not tied to a test failure really, it's where it will mainly be used but not tied. Would suggest changing this to `Clean the test database environment`.