[ussuri][goal] Drop python 2.7 support and testing3.0.0

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, conf.py, and tox.ini from cruft.

Change-Id: Icb08c704cb5d0d8004d0a5408822c9d53ae9c728

10 files changed, 17 insertions, 58 deletions

diff --git a/.zuul.yaml b/.zuul.yaml
index 6118e61..63db13b 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -1,6 +1,6 @@
 - job:
-    name: cliff-tox-py27-neutronclient-tip
-    parent: openstack-tox-py27
+    name: cliff-tox-py37-neutronclient-tip
+    parent: openstack-tox-py37
     description: |
       Run unit tests for neutronclient with master branch of cliff
 
@@ -22,19 +22,17 @@
 - project:
     templates:
       - check-requirements
-      - lib-forward-testing
       - lib-forward-testing-python3
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - publish-openstack-docs-pti
     check:
       jobs:
-        - cliff-tox-py27-neutronclient-tip
-        - osc-tox-unit-tips:
+        - cliff-tox-py37-neutronclient-tip
+        - osc-tox-py36-tips:
             branches: ^master$
     gate:
       jobs:
-        - cliff-tox-py27-neutronclient-tip
-        - osc-tox-unit-tips:
+        - cliff-tox-py37-neutronclient-tip
+        - osc-tox-py36-tips:
             branches: ^master$
diff --git a/doc/requirements.txt b/doc/requirements.txt
index d6d8d0a..bfd5f87 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,6 +1,5 @@
 # The order of packages is significant, because pip processes them in the order
 # 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,<2.0.0,>=1.6.2;python_version=='2.7'  # BSD
-sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4'  # BSD
+sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2  # BSD
 openstackdocstheme>=1.18.1 # Apache-2.0
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 63a342f..0421f14 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -14,7 +14,6 @@
 
 import datetime
 import os.path
-import subprocess
 import sys
 
 # make openstackdocstheme an optional dependency. cliff is a low level lib
@@ -55,7 +54,6 @@ if has_openstackdocstheme:
 repository_name = 'openstack/cliff'
 bug_project = 'python-cliff'
 bug_tag = ''
-html_last_updated_fmt = '%Y-%m-%d %H:%M'
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -73,17 +71,6 @@ master_doc = 'index'
 project = u'cliff'
 copyright = u'2012-%s, Doug Hellmann' % datetime.datetime.today().year
 
-# The version info for the project you're documenting, acts as replacement for
-# |version| and |release|, also used in various other places throughout the
-# built documents.
-#
-# The short X.Y version.
-version = subprocess.Popen(['cd ../..; python setup.py --version'],
-                           shell=True, stdout=subprocess.PIPE).stdout.read()
-version = version.strip()
-# The full version, including alpha/beta/rc tags.
-release = version
-
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
 # language = None
diff --git a/doc/source/install/index.rst b/doc/source/install/index.rst
index 406bea0..30b4532 100644
--- a/doc/source/install/index.rst
+++ b/doc/source/install/index.rst
@@ -5,7 +5,7 @@
 Python Versions
 ===============
 
-cliff is being developed under Python 2.7 and tested with Python 3.5.
+cliff is being developed under Python 3.
 
 Dependencies
 ============
diff --git a/lower-constraints.txt b/lower-constraints.txt
index 1e0ab80..6a163a5 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -33,5 +33,4 @@ testrepository==0.0.18
 testscenarios==0.4
 testtools==2.2.0
 traceback2==1.4.0
-unicodecsv==0.8.0;python_version<'3.0'
 unittest2==1.1.0
diff --git a/requirements.txt b/requirements.txt
index 6c3fe98..c5f88ce 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,5 +7,4 @@ PrettyTable<0.8,>=0.7.2 # BSD
 pyparsing>=2.1.0 # MIT
 six>=1.10.0 # MIT
 stevedore>=1.20.0 # Apache-2.0
-unicodecsv>=0.8.0;python_version<'3.0' # BSD
 PyYAML>=3.12 # MIT
diff --git a/setup.cfg b/setup.cfg
index 02b9fba..f755402 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -5,15 +5,16 @@ author = OpenStack
 author-email = openstack-discuss@lists.openstack.org
 summary = Command Line Interface Formulation Framework
 home-page = https://docs.openstack.org/cliff/latest/
+python-requires = >=3.6
 classifier =
     Development Status :: 5 - Production/Stable
     License :: OSI Approved :: Apache Software License
     Programming Language :: Python
-    Programming Language :: Python :: 2
-    Programming Language :: Python :: 2.7
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: Implementation :: CPython
     Intended Audience :: Developers
     Environment :: Console
 
@@ -55,11 +56,3 @@ cliff.demo =
 cliff.demo.hooked =
     sample-hook = cliffdemo.hook:Hook
 
-[bdist_wheel]
-universal = 1
-
-[build_sphinx]
-all-files = 1
-warning-is-error = 1
-build-dir = doc/build
-source-dir = doc/source
diff --git a/setup.py b/setup.py
index 566d844..f63cc23 100644
--- a/setup.py
+++ b/setup.py
@@ -16,14 +16,6 @@
 # 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)
diff --git a/test-requirements.txt b/test-requirements.txt
index 45987f4..d69d358 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -12,8 +12,7 @@ coverage!=4.4,>=4.0 # Apache-2.0
 
 # sphinx is required in test-requirements in addition to doc/requirements
 # because there is a sphinx extension that has tests
-sphinx!=1.6.6,!=1.6.7,<2.0.0,>=1.6.2;python_version=='2.7'  # BSD
-sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2;python_version>='3.4'  # BSD
+sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2  # BSD
 
 # Bandit security code scanner
 bandit>=1.1.0 # Apache-2.0
diff --git a/tox.ini b/tox.ini
index 64d19d2..bc9f04a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,17 +1,16 @@
 [tox]
-minversion = 2.0
-envlist = py27,py37,pep8
+minversion = 3.1.0
+envlist = py37,pep8
+ignore_basepython_conflict = True
 
 [testenv]
+basepython = python3
 setenv =
     VIRTUAL_ENV={envdir}
-    BRANCH_NAME=master
-    CLIENT_NAME=cliff
     OS_STDOUT_CAPTURE=1
     OS_STDERR_CAPTURE=1
     OS_TEST_TIMEOUT=60
 distribute = False
-install_command = pip install {opts} {packages}
 commands =
   python setup.py test --coverage --coverage-package-name=cliff --slowest --testr-args='{posargs}'
   coverage report --show-missing
@@ -21,7 +20,6 @@ deps =
   -r{toxinidir}/requirements.txt
 
 [testenv:pep8]
-basepython = python3
 deps =
   -r{toxinidir}/test-requirements.txt
   flake8
@@ -31,7 +29,6 @@ commands =
   bandit -c bandit.yaml -r cliff -x tests -n5
 
 [testenv:venv]
-basepython = python3
 # TODO(modred) remove doc/requirements.txt once the openstack-build-sphinx-docs
 # job is updated.
 deps =
@@ -40,22 +37,18 @@ deps =
 commands = {posargs}
 
 [testenv:neutronclient-tip]
-basepython = python2.7
 deps = os:openstack/python-neutronclient:python-neutronclient
 commands = {toxinidir}/integration-tests/neutronclient-tip.sh {envdir}
 
 [testenv:openstackclient-tip]
-basepython = python2.7
 deps = os:openstack/python-openstackclient:python-openstackclient
 commands = {toxinidir}/integration-tests/openstackclient-tip.sh {envdir}
 
 [testenv:docs]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
-commands = sphinx-build -b html doc/source doc/build/html
+commands = sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt