Cleanup py27 support

This repo is now testing only with Python 3, so let's make
a few cleanups:
- Remove python 2.7 stanza from setup.py
- Add requires on python >= 3.6 to setup.cfg so that pypi and pip
  know about the requirement
- Update classifiers
- Use newer openstackdocstheme and Sphinx versions
- Build docs, don't publish yet

Change-Id: I2de4e1dbac061002940f80b2cf129dc343343a0d

.zuul.yaml

@@ -1,5 +1,6 @@
 - project:
     templates:
+      - build-openstack-docs-pti
       - check-requirements
       - horizon-non-primary-django-jobs
       - openstack-cover-jobs-horizon

lower-constraints.txt

@@ -45,7 +45,7 @@ munch==2.5.0
 netaddr==0.7.19
 netifaces==0.10.9
 nodeenv==0.9.4
-openstackdocstheme==1.20.0
+openstackdocstheme==2.0.0
 openstacksdk==0.43.0
 os-client-config==2.0.0
 os-service-types==1.7.0
@@ -82,7 +82,7 @@ python-swiftclient==3.9.0
 pytz==2019.3
 PyYAML==5.3.1
 rcssmin==1.0.6
-reno==1.8.0
+reno==2.5.0
 requests==2.23.0
 requestsexceptions==1.4.0
 rfc3986==1.3.2
@@ -92,7 +92,7 @@ semantic-version==2.8.4
 simplejson==3.17.0
 six==1.14.0
 snowballstemmer==2.0.0
-Sphinx==1.6.2
+Sphinx==2.0.0
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-devhelp==1.0.2
 sphinxcontrib-htmlhelp==1.0.3

setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = Adrian Turjak
 author-email = adriant@catalyst.net.nz
 home-page = https://github.com/catalyst/adjutant-ui
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Framework :: Django
@@ -14,9 +15,12 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
+    Programming Language :: Python :: Implementation :: CPython
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
 
 [files]
 packages =

setup.py

@@ -13,17 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# THIS FILE IS MANAGED BY THE GLOBAL REQUIREMENTS REPO - DO NOT EDIT
 import setuptools
 
-# In python < 2.7.4, a lazy loading of package `pbr` will break
-# setuptools if some other modules registered functions in `atexit`.
-# solution from: http://bugs.python.org/issue15881#msg170215
-try:
-    import multiprocessing  # noqa
-except ImportError:
-    pass
-
 setuptools.setup(
     setup_requires=['pbr>=1.8'],
     pbr=True)

test-requirements.txt

@@ -10,10 +10,10 @@
 hacking>=3.0,<3.1 # Apache-2.0
 coverage>=4.0 # Apache-2.0
 nodeenv>=0.9.4 # BSD
-reno>=1.8.0 # Apache-2.0
+reno>=2.5.0 # Apache-2.0
 selenium>=2.50.1 # Apache-2.0
-sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2 # BSD
+sphinx!=2.1.0,>=2.0.0 # BSD
 testtools>=1.4.0 # MIT
 # This also needs xvfb library installed on your OS
 xvfbwrapper>=0.1.3 #license: MIT
-openstackdocstheme>=1.20.0 # Apache-2.0
+openstackdocstheme>=2.0.0 # Apache-2.0