Setting up user permissions and privileges in the new CantusDB

In CantusDB's admin interface, the following groups should be added:

• "contributor"
• "editor"
• "project manager"

Please ensure that the group names are exactly the same as above (case-sensitive). The code for user permissions depends on this.

This should enable the following workflow:

1. a new user is created in the Django admin interface
2. the user is assigned to one or more of the groups above
3. the user is assigned to sources that they have privilege to edit (provided they are in a group that allows them to edit sources).