Fixes to the admin script
Slugs cannot be used as IDs any more
Removing custom slugify method
Adapted tests to new id type
Added is_public confirmation to admin script
Trailing slashes

Resources now require trailing slashes. They were added because requesting a
resource with a trailing slash would 404. Now all resources without trailing
slash will be redirected.
Double slashes

Added a check to prevent double slashes errors.
Got rid of another with statement