Workaround ansible bug related to delegate_to

Currently the delegate_to doesnt happen and the neutron role creation is
attempted once on the first server and is skipped. The re-ordering of hosts in
site.yml seems to make the first host to be one inside neutron-server group
yielding the expected results. This patch needs to be re-visited as soon as a
version of ansible is chosen that fixes the issues with delegate_to

Co-Authored-By: Steven Dake <stdake@cisco.com>
Co-Authored-By: Vikram Hosakote <vhosakot@cisco.com>
Co-Authored-By: Nate Potter <nathaniel.potter@intel.com>
Co-Authored-By: Ganesh Mahalingam <ganesh.mahalingam@intel.com>
Change-Id: Ia712b323aa9d750d470a11ee899ab1b3054a903f
Partial-Bug: #1546789
(cherry picked from commit 0bba5fe000)

ansible/site.yml

@@ -104,12 +104,12 @@
         when: enable_nova | bool }
 
 - hosts:
-    - compute
-    - manila-share
+    - neutron-server
     - neutron-dhcp-agent
     - neutron-l3-agent
     - neutron-metadata-agent
-    - neutron-server
+    - compute
+    - manila-share
     - rabbitmq
     - memcached
   roles: