Add boto to test requirements.
Install submodule structure.

* Enables proper relative imports.
Enable relative imports on db migrations.
Comment unused import.
Hackishly replace strtobool.

* distutils is not readily available in all platforms.
Fix imports in features folder.
Revert "Revert PR #621"

This reverts commit d32db58bb3f693de33776229c76185d270d32a6e.
Enable all import errors.