Revert "Disable fullstack job from gate and make it non-voting"

This reverts commit d33e5f5c17.

After bugs [1] and [2] are fixed, fullstack job got back to acceptable failure rates and we can make it again voting and gating.

[1] https://bugs.launchpad.net/neutron/+bug/1820865
[2] https://bugs.launchpad.net/neutron/+bug/1820870

Change-Id: I6feaaf563df93096f063e487a3ed086b93adcb0e
(cherry picked from commit 699bb45a6c)

.zuul.yaml

@@ -62,13 +62,7 @@
       jobs:
         - neutron-functional
         - neutron-functional-python27
-        # NOTE(slaweq) Because of bugs:
-        # https://bugs.launchpad.net/neutron/+bug/1820865 and
-        # https://bugs.launchpad.net/neutron/+bug/1820870
-        # which cause fullstack to be very unstable we need to disable it
-        # from gate queue for now.
-        # TODO(slaweq): Restore fullstack job when above bugs will be fixed
-        #- neutron-fullstack
+        - neutron-fullstack
         - neutron-tempest-dvr
         - neutron-tempest-linuxbridge
         - neutron-tempest-iptables_hybrid
@@ -159,7 +153,6 @@
         # /opt/stack/logs is default logs directory defined in neutron's
         # tox.ini file
         '{{ devstack_base_dir }}/logs/dsvm-fullstack-logs': logs
-    voting: false
 
 - job:
     name: neutron-rally-task