When auto-registration of repos is enabled, test moving repositories in and out of organization

[jhrozek]

There are several use-cases that we need to test related to repository auto-enrollment:

• a repository is moved from an org to another, both are registered in the same project
• a repository is moved from an org to another, both are registered in different projects
• a repository is moved from an org to another, one of them is not registered

Presumably we need to treat this as a delete and add but worth testing explicitly.