Use Horizon project template for django jobs

Horizon defined a project template 'horizon-non-primary-django-jobs'
for django jobs. This patch use that template to run django jobs
here. For information please refer [1]

Explicit testenv definitions (py27, py36, py37) are dropped
as tox handles them automatically and they are unnecessary.

[1] https://review.opendev.org/#/c/681969/

Change-Id: Iff4bb3e088bb522ee336b324b0756efe84e2fde4

.zuul.yaml

@@ -1,6 +1,7 @@
 - project:
     templates:
       - check-requirements
+      - horizon-non-primary-django-jobs
       - openstack-python-jobs
       - openstack-python3-train-jobs
       - release-notes-jobs-python3

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = pep8,py27,py36,py37
+envlist = pep8,py27,py36,py37,py3-{dj111,dj22}
 minversion = 2.0
 skipsdist = True
 
@@ -17,27 +17,15 @@ deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
-commands = python manage.py test {posargs} --settings=masakaridashboard.test.settings --verbosity 2
+commands =
+   dj111: pip install django>=1.11,<2
+   dj22: pip install django>=2.2,<2.3
+   python manage.py test {posargs} --settings=masakaridashboard.test.settings --verbosity 2
 
 [testenv:pep8]
 basepython = python3
 commands = flake8 {posargs}
 
-[testenv:py27]
-basepython = python2.7
-commands =
-   {[testenv]commands}
-
-[testenv:py36]
-basepython = python3.6
-commands =
-   {[testenv]commands}
-
-[testenv:py37]
-basepython = python3.7
-commands =
-    {[testenv]commands}
-
 [testenv:venv]
 basepython = python3
 commands = {posargs}