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

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

python-barbicanclient 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: Id55914141099650752027aa9dc0ad8a90528a2e9

doc/requirements.txt

@@ -1,7 +1,6 @@
 # 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,>=1.6.2,<2.0.0;python_version=='2.7'  # BSD
-sphinx>=1.8.0,!=2.1.0;python_version>='3.4'  # BSD
+sphinx>=1.8.0,!=2.1.0  # BSD
 sphinxcontrib-svg2pdfconverter>=0.1.0 # BSD
 openstackdocstheme>=1.20.0 # Apache-2.0

doc/source/contributor/testing.rst

@@ -23,8 +23,8 @@ with the following command:
 
 .. code-block:: bash
 
-    # Executes tests on Python 2.7
-    tox -e py27
+    # Executes tests on Python 3.7
+    tox -e py37
 
 .. note::
 
@@ -40,11 +40,11 @@ with the following command:
 
         # runs a single test with the function named
         # test_should_entity_str
-        tox -e py27 -- test_should_entity_str
+        tox -e py37 -- test_should_entity_str
 
         # runs only tests in the WhenTestingSecrets class and
         # the WhenTestingOrderManager class
-        tox -e py27 -- '(WhenTestingSecrets|WhenTestingOrderManager)'
+        tox -e p37 -- '(WhenTestingSecrets|WhenTestingOrderManager)'
 
     The function name or class specified must be one located in the
     `barbicanclient/tests` directory.

releasenotes/notes/drop-py-2-7-50042a0e2227c095.yaml

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

setup.cfg

@@ -13,11 +13,9 @@ 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
 
 
 [files]

tox.ini

@@ -1,9 +1,11 @@
 [tox]
-minversion = 2.0
-envlist = py35,py36,py27,pep8
+minversion = 3.1.1
+envlist = py37,py36,pep8
 skipsdist = True
+ignore_basepython_conflict = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 install_command = pip install {opts} {packages}
 setenv =
@@ -25,15 +27,12 @@ commands =
 whitelist_externals = rm
 
 [testenv:debug]
-basepython = python3
 commands = oslo_debug_helper -t barbicanclient/tests {posargs}
 
 [testenv:pep8]
-basepython = python3
 commands = flake8 {posargs}
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:docs]
@@ -48,7 +47,6 @@ commands=
 whitelist_externals = rm
 
 [testenv:pdf-docs]
-basepython = python3
 deps = {[testenv:docs]deps}
 whitelist_externals =
   make
@@ -70,7 +68,6 @@ show-source = True
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt