allow maintainers to abandon changes

Changes can become stale and owners can go MIA so allow maintainers to
abandon changes as they see fit.

Change-Id: I095bccb642bf7e42f8f9441cdc9b00761a653c65
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/project.config b/project.config
index 80d833b..1a4be33 100644
--- a/project.config
+++ b/project.config
@@ -5,6 +5,7 @@
 [access "refs/heads/*"]
 	submit = group Registered Users
 	label-Code-Review = -2..+2 group github/openbmc/all-maintainers
+	abandon = group github/openbmc/all-maintainers
 [access "refs/meta/config"]
 	label-Code-Review = -1..+1 group Registered Users
 	label-Verified = -1..+1 group Administrators