django-fsm 5.0.1

• Fix from django_fsm import * without Django installed by exporting only
  the available core API, and add regression tests for both import modes.
• Document the 5.0 transition timing change and clarify that direct transition
  calls do not check user permissions automatically.
• Include CONTRIBUTING.rst in source distributions and link to it on GitHub.
• Update the package homepage to https://github.com/viewflow/django-fsm.