Bump observatory_pub_packages in DEPS

DEPS

 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 vars = {
   # The dart_root is the root of our sdk checkout. This is normally
   # simply sdk, but if using special gclient specs it can be different.
   "dart_root": "sdk",
 
   # The svn location to pull out dependencies from
@@ skipping 59 matching lines @@
   "json_rpc_2_tag": "@1.1.1",
   "linter_rev": "@1df9178fbb475c77658531b3d702ac9e615f9714",
   "logging_rev": "@85d83e002670545e9039ad3985f0018ab640e597",
   "markdown_rev": "@4aaadf3d940bb172e1f6285af4d2b1710d309982",
   "matcher_tag": "@0.12.0",
   "metatest_rev": "@e5aa8e4e19fc4188ac2f6d38368a47d8f07c3df1",
   "mime_rev": "@75890811d4af5af080351ba8a2853ad4c8df98dd",
   "mustache4dart_rev" : "@5724cfd85151e5b6b53ddcd3380daf188fe47f92",
   "oauth2_rev": "@1bff41f4d54505c36f2d1a001b83b8b745c452f5",
   "observe_rev": "@eee2b8ec34236fa46982575fbccff84f61202ac6",
-  "observatory_pub_packages_rev": "@cdc4b3d4c15b9c0c8e7702dff127b440afbb7485",
+  "observatory_pub_packages_rev": "@a731d3b1caf27b45aecdce9378b87a510240264d",
   "package_config_rev": "@0.1.3",
   "path_tag": "@1.3.6",
   "petitparser_rev" : "@37878",
   "ply_rev": "@604b32590ffad5cbb82e4afef1d305512d06ae93",
   "plugin_tag": "@0.1.0",
   "pool_rev": "@e454b4b54d2987e8d2f0fbd3ac519641ada9bd0f",
   "pub_rev": "@1c08b841158e33b8090bb07e5c39df830db58d44",
   "pub_cache_tag": "@v0.1.0",
   "pub_semver_tag": "@1.2.1",
   "quiver_tag": "@0.21.4",
@@ skipping 294 matching lines @@
       "--bucket",
       "dart-dependencies",
       "--recursive",
       "--auto_platform",
       "--extract",
       "--directory",
       Var('dart_root') + "/tools/sdks",
     ],
   },
 ]