[ussuri][goal] Drop python 2.7 support and testing

OpenStack is dropping the py2.7 support in ussuri cycle.

Complete discussion & schedule can be found in
- http://lists.openstack.org/pipermail/openstack-discuss/2019-October/010142.html
- https://etherpad.openstack.org/p/drop-python2-support

Ussuri Communtiy-wide goal:
https://governance.openstack.org/tc/goals/selected/ussuri/drop-py27.html

Cleanup setup.cfg and remove old cruft.

Change-Id: I706a33405c71bb6dd1c358e7c0f5fea6dc96f7ec

oslo.{{cookiecutter.module_name}}/doc/requirements.txt

@@ -2,7 +2,6 @@
 # of appearance. Changing the order has an impact on the overall integration
 # process, which may cause wedges in the gate later.
 
-sphinx!=1.6.6,!=1.6.7,>=1.6.2,<2.0.0;python_version=='2.7' # BSD
-sphinx!=1.6.6,!=1.6.7,>=1.6.2;python_version>='3.4' # BSD
+sphinx>=2.0 # BSD
 openstackdocstheme>=1.20.0
 sphinxcontrib-apidoc>=0.2.0 # BSD

oslo.{{cookiecutter.module_name}}/setup.cfg

@@ -6,6 +6,7 @@ description-file =
 author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 home-page = http://launchpad.net/oslo
+python-requires = >=3.6
 classifier =
     Environment :: OpenStack
     Intended Audience :: Information Technology
@@ -13,24 +14,17 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
-    Programming Language :: Python :: 2
-    Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.5
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: Implementation :: CPython
+
 
 [files]
 packages =
     oslo_{{ cookiecutter.module_name }}
 
-[build_sphinx]
-source-dir = doc/source
-build-dir = doc/build
-all_files = 1
-warning-is-error = 1
-
-[upload_sphinx]
-upload-dir = doc/build/html
-
 [compile_catalog]
 directory = oslo.{{cookiecutter.module_name}}/locale
 domain = oslo.{{cookiecutter.module_name}}
@@ -44,6 +38,3 @@ input_file = oslo.{{cookiecutter.module_name}}/locale/oslo.{{cookiecutter.module
 keywords = _ gettext ngettext l_ lazy_gettext
 mapping_file = babel.cfg
 output_file = oslo.{{cookiecutter.module_name}}/locale/oslo.{{cookiecutter.module_name}}.pot
-
-[wheel]
-universal = true

oslo.{{cookiecutter.module_name}}/tox.ini

@@ -1,19 +1,18 @@
 [tox]
-minversion = 3.1
-envlist = py36,py27,pep8
-skipsdist = True
+minversion = 3.1.0
+envlist = py36,pep8
 ignore_basepython_conflict = True
+skipsdist = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 deps =
     -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
     -r{toxinidir}/test-requirements.txt
 commands = stestr run --slowest {posargs}
-basepython = python3
 
 [testenv:lower-constraints]
-basepython = python3
 deps = -c{toxinidir}/lower-constraints.txt
        -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt

tools/test_tox_targets.sh

@@ -30,4 +30,4 @@ def test_api():
     pass
 EOF
 
-tox -e pep8,py27,py36,docs,lower-constraints,cover
+tox -e pep8,py36,docs,lower-constraints,cover

tox.ini

@@ -1,9 +1,11 @@
 [tox]
-minversion = 2.0
+minversion = 3.1.1
 envlist = cookiecutter
 skipsdist = True
+ignore_basepython_conflict = True
 
 [testenv:cookiecutter]
+basepython = python3
 deps = cookiecutter
 commands =
     {toxinidir}/tools/test_tox_targets.sh