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

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

python-freezerclient is ready with python 3 and ok to drop the
python 2.7 support.

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

Change-Id: Id0901d32660b9b643d3d2eb35e77627dfca6b944

.zuul.yaml

@@ -2,8 +2,7 @@
     templates:
       - check-requirements
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
-      - openstack-python3-train-jobs
+      - openstack-python3-ussuri-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3
     check:

doc/requirements.txt

@@ -1,4 +1,3 @@
-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,!=2.1.0,>=1.6.2;python_version>='3.4' # BSD
 openstackdocstheme>=1.20.0 # Apache-2.0
 reno>=2.5.0 # Apache-2.0

doc/source/contributor/testing.rst

@@ -6,11 +6,8 @@ test targets that can be run to validate the code.
 ``tox -e pep8``
   Style guidelines enforcement.
 
-``tox -e py27``
-  Traditional unit testing (Python 2.7).
-
-``tox -e py35``
-  Traditional unit testing (Python 3.5).
+``tox -e py37``
+  Traditional unit testing (Python 3.7).
 
 ``tox -e cover``
   Generate a coverage report on unit testing.

releasenotes/notes/drop-py-2-7-9a3fc069f66d62bc.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Python 2.7 support has been dropped. Last release of python-freezerclient
+    to support python 2.7 is OpenStack Train. The minimum version of Python now
+    supported is Python 3.6.

setup.cfg

@@ -9,8 +9,6 @@ author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/python-freezerclient/latest/
 classifier =
     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

tox.ini

@@ -1,9 +1,11 @@
 [tox]
-minversion = 2.0
-envlist = py27,py36,py37,pep8,pylint,docs
+minversion = 3.1.1
+envlist = py36,py37,pep8,pylint,docs
 skipsdist = True
+ignore_basepython_conflict = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 deps =
     -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
@@ -34,12 +36,8 @@ python_files = test_*.py
 norecursedirs  = .tox .venv
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
-[testenv:py27]
-basepython = python2.7
-
 [testenv:py36]
 basepython = python3.6
 
@@ -47,16 +45,13 @@ basepython = python3.6
 basepython = python3.7
 
 [testenv:docs]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -b html doc/source doc/build/html
 
 [testenv:pep8]
-basepython = python3
 commands = flake8 freezerclient
 
 [testenv:pylint]
-basepython = python3
 commands = pylint --rcfile .pylintrc freezerclient
 
 [flake8]
@@ -74,7 +69,6 @@ exclude = .venv,.tox,dist,doc,*egg,releasenotes
 
 
 [testenv:releasenotes]
-basepython = python3
 deps =
     -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
     -r{toxinidir}/requirements.txt
@@ -82,7 +76,6 @@ deps =
 commands = sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt