Rename local_settings to just local

The name local_settings was used when there was settings/ directory,
so I needed a way to separate settings.py from local_settings.py
The _settings suffix is useless though, we can refer this file
as settings/local
Update .gitignore as well to reflect the renamed settings/local
Merge remote-tracking branch 'tampakrap/local_settings_rename'

Conflicts:
	okupy/settings/__init__.py