Stay on top of commits to Drupal 7 project

[jenlampton]

There have been several releases of the Drupal 7 project module since this version was forked. We should see if we want any of those commits on this project.

Git tag 7.x-2.0-alpha1

• [ ] | #985994 Invoke a hook when project release XML has been written
• [ ] | #2479625 by aaronbauman, Pere Orga: Add taxonomy dependency to project releases

Git tag 7.x-2.0-alpha2

• [x] | N/A #2600432 Add UPGRADE.txt
• [ ] | #1925728 Schema inconsistent: several columns difference on "not null"

Git tag 7.x-2.0-alpha3

• [ ] | #2163051 Cannot create releases
• [ ] | #2615184 Update project_release_files view, add content pane display

See also:

• https://github.com/backdrop-contrib/project/issues/45
• https://github.com/backdrop-contrib/project/issues/46