Merge branch 'master' into patch-1

Author: djdefi

docs/requirements.md

@@ -61,6 +61,8 @@ snapshot of GitHub Enterprise Server 2.11, the target GitHub Enterprise Server a
 be running GitHub Enterprise Server 2.12.x or 2.13.x. You can't restore a snapshot from
 2.10 to 2.13, because that's three releases ahead.
 
+**Note**: You _cannot_ restore a backup created from a newer verison of GitHub Enterprise Server to an older version. For example, an attempt to restore a snapshot of GitHub Enterprise Server 2.21 to a GitHub Enterprise Server 2.20 environment will fail with an error of `Error: Snapshot can not be restored to an older release of GitHub Enterprise Server.`.
+
 [1]: https://www.gnu.org/software/bash/
 [2]: https://git-scm.com/
 [3]: https://www.openssh.com/