Use Zuul v3 feature

Move from project-config the job definitions for python-redfish with
the .zuul.yaml config file (except publish-to-pypi) and adapt templates
to new v3 naming style, thanks to Andreas Jaeger

Change-Id: I96d47f8b754864053cb46e0c89e123cac6f571cf

.zuul.yaml

@@ -0,0 +1,13 @@
+---
+- project:
+    templates:
+        - openstack-python-jobs
+        - openstack-python35-jobs
+        - openstack-python36-jobs
+        - openstack-python37-jobs
+    check:
+      jobs:
+        - openstack-tox-pep8
+    gate:
+      jobs:
+        - openstack-tox-pep8

requirements.txt

@@ -5,7 +5,8 @@
 pbr>=0.8
 tortilla>=0.4.1
 Jinja2>=2.7.3
-Sphinx>=1.2.3
+Sphinx>=1.2.3,<2.0; python_version < '3'
+Sphinx>=1.2.3; python_version >= '3'
 docopt>=0.6.2
 simplejson>=3.8.1
 requests>=2.9.1

tox.ini

@@ -1,6 +1,6 @@
 [tox]
-minversion = 1.6
+minversion = 2.0
-envlist = py36,py35,py27,docs
+envlist = py36,py35,docs
 skipsdist = True
 
 [testenv]