Don't publish Differential "create" action to Asana

Summary: Ref T2852. Currently there's effectively a double notification: one for creating the task, and one for the "alincoln created this revision" story. Drop the "create" story.

Test Plan: Used `bin/feed republish` to republish "create" and non-"create" stories. Verified "create" was dropped as unsupported, while non-"create" went through.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2852

Differential Revision: https://secure.phabricator.com/D6589

Author: epriestley

src/applications/differential/doorkeeper/DifferentialDoorkeeperRevisionFeedStoryPublisher.php

@@ -4,7 +4,23 @@ final class DifferentialDoorkeeperRevisionFeedStoryPublisher
   extends DoorkeeperFeedStoryPublisher {
 
   public function canPublishStory(PhabricatorFeedStory $story, $object) {
-    return ($object instanceof DifferentialRevision);
+    if (!($object instanceof DifferentialRevision)) {
+      return false;
+    }
+
+    // Don't publish the "create" story, since pushing the object into Asana
+    // naturally generates a notification which effectively serves the same
+    // purpose as the "create" story.
+
+    $action = $story->getStoryData()->getValue('action');
+    switch ($action) {
+      case DifferentialAction::ACTION_CREATE:
+        return false;
+      default:
+        break;
+    }
+
+    return true;
   }
 
   public function willPublishStory($object) {