Revert "Mark cinder/py35 cross job as non-voting"

This reverts commit a61478df1a5736fdc2bcb9f07fceb52d2a9fd804.

The high failure rate on py35 cinder unit tests has been mitigated by
cleaning up the logging output during the runs.

Change-Id: Ia4112ac78c800fb2ac8ee1fa68f0ab1f80803e59

.zuul.d/cross-jobs.yaml

@@ -34,8 +34,6 @@
     parent: requirements-cross-test
     description: Run cross-project tests on cinder with py35.
     required-projects: openstack/cinder
-    # cinder seems to have very nasty races in its unit tests
-    voting: false
     vars:
       tox_envlist: py35
 

.zuul.d/project.yaml

@@ -61,6 +61,8 @@
             branches: ^(?!stable/(newton|ocata|pike)).*$
         - requirements-tox-validate-projects
         - cross-cinder-py27
+        - cross-cinder-py35:
+            branches: ^(?!stable/(newton|ocata)).*$
         - cross-glance-py27
         - cross-glance-py35:
             branches: ^(?!stable/(newton|ocata)).*$