Fix py27 commands failed
Fix py27 commands failed

When run tox -e py27.

File "/home/liwei/code/watcher-dashboard/watcher_dashboard/
      test/settings.py", line 51, in <module>
    TEMPLATE_CONTEXT_PROCESSORS += (
NameError: name 'TEMPLATE_CONTEXT_PROCESSORS' is not defined
ERROR: InvocationError: '/home/liwei/code/watcher-dashboard/
.tox/py27/bin/python manage.py
test --settings=watcher_dashboard.test.settings
--exclude-dir=watcher_dashboard/test/integration_tests watcher_dashboard'

ERROR: py27: commands failed.

We should remove + operator for py27 commands success.

Closes-Bug: #1625999
Change-Id: I2ef8c0cdf1ec82ff09233341482a36b3b717e172

openstack/watcher-dashboard,openstack/watcher-dashboard,openstack/watcher-dashboard,openstack/watcher-dashboard