Update Coordination.md claiming issue 21312

EmandM · EmandM · commit e97ce047e6b1 · 2017-03-21T15:37:10.000+13:00
diff --git a/Coordination.md b/Coordination.md
@@ -29,6 +29,7 @@ Issue number: group name (no links to elasticsearch, just the number - sort by i
 * 18543: Oink
 * 19391: FDJ
 * 20912: Evil_Engineers
+* 21312: Rocky Road
 * 21418: marathon
 * 21772: Random 1
 * 21802: JQ
