Set an icon for Maniphest story points

Summary: It's an icon. For story points.

Test Plan: Set some points, see icon.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D17915

src/applications/maniphest/xaction/ManiphestTaskPointsTransaction.php

@@ -71,6 +71,10 @@ final class ManiphestTaskPointsTransaction
     return $errors;
   }
 
+  public function getIcon() {
+    return 'fa-calculator';
+  }
+
   private function getValueForPoints($value) {
     if (!strlen($value)) {
       $value = null;