GH-983: Stabilise the sort order of the listing

opentech/static_src/src/app/src/containers/ByRoundListing.js

@@ -60,7 +60,8 @@ class ByRoundListing extends React.Component {
         const { isLoading, rounds, submissions } = this.props;
         if (isLoading)
             return []
-        return submissions.map(submission => submission.round)
+        return submissions.sort((a, b) => a.id - b.id )
+                          .map(submission => submission.round)
                           .filter((round, index, arr) => arr.indexOf(round) === index)
                           .map((round, i) => ({
                               display: rounds[parseInt(round)].title,