Small cleanups

Remove py2.7 lines from setup.py.
Remove obsolete build_sphinx lines from setup.cfg.
Remove html_last_updated_fmt from doc/source/conf.py, it's not needed
with newer openstackdocstheme.
Update openstackdocstheme requirement.
Update upper-constraints URL.

Change-Id: I492209291a39699dee1ea75e5109c4d1ac9c725f

doc/requirements.txt

@@ -1,3 +1,3 @@
 sphinx>=1.8.0,!=2.1.0 # BSD
-openstackdocstheme>=1.18.1 # Apache-2.0
+openstackdocstheme>=1.32.1 # Apache-2.0
 reno>=2.5.0 # Apache-2.0

setup.cfg

@@ -62,12 +62,6 @@ flake8.extension =
 pep257 =
   flake8-docstrings==0.2.1.post1 # MIT
 
-[build_sphinx]
-all_files = 1
-build-dir = doc/build
-source-dir = doc/source
-warning-is-error = 1
-
 [egg_info]
 tag_build =
 tag_date = 0

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>=2.0.0'],
     pbr=True)

tox.ini

@@ -9,7 +9,7 @@ basepython = python3
 usedevelop = True
 install_command = pip install {opts} {packages}
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/requirements.txt
   -r{toxinidir}/test-requirements.txt
 commands =
@@ -31,7 +31,7 @@ commands =
 
 [testenv:docs]
 deps =
-  -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+  -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
 commands =
   sphinx-build -W -b html doc/source doc/build/html