Summary: Fixes T4122. Ref T2230. Instead of storing credentials on each repository, store them in Passphrase. This allows easy creation/management of many repositories which share credentials.
Test Plan:
- Upgraded repositories.
- Created and edited repositories.
- Pulled HTTP and SSH repositories.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T2230, T4122
Differential Revision: https://secure.phabricator.com/D7629
