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

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

karbor-dashboard 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

Depends-On: https://review.opendev.org/#/c/693631/
Change-Id: Ic69bd25a9be7b512c0341e524e67e04f81217214

.zuul.yaml

@@ -1,6 +1,5 @@
 - project:
     templates:
       - horizon-non-primary-django-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - check-requirements

releasenotes/notes/drop-py-2-7-b0d1b4d66110f40e.yaml

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

setup.cfg

@@ -13,8 +13,6 @@ 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 :: 3.6
     Programming Language :: Python :: 3.7

test-requirements.txt

@@ -15,8 +15,7 @@ mox3>=0.20.0 # Apache-2.0
 nodeenv>=0.9.4 # BSD
 oslosphinx>=4.7.0 # Apache-2.0
 selenium>=2.50.1 # Apache-2.0
-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
+sphinx!=1.6.6,!=1.6.7,!=2.1.0,>=1.6.2 # BSD
 testtools>=2.2.0 # MIT
 # This also needs xvfb library installed on your OS
 xvfbwrapper>=0.1.3 #license: MIT

tox.ini

@@ -1,9 +1,11 @@
 [tox]
-envlist = py27,py37,py3-{dj111,dj22},pep8
-minversion = 1.6
+envlist = py37,py3-{dj111,dj22},pep8
+minversion = 3.1.1
 skipsdist = True
+ignore_basepython_conflict = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 install_command = pip install -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master} {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
@@ -18,32 +20,26 @@ commands =
    {toxinidir}/manage.py test karbor_dashboard --settings=karbor_dashboard.test.settings
 
 [testenv:pep8]
-basepython = python3
 commands =
   /bin/bash run_tests.sh -N --pep8
   /bin/bash run_tests.sh -N --makemessages --check-only
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:cover]
-basepython = python3
 commands = /bin/bash run_tests.sh -N --no-pep8 --coverage {posargs}
 
-[testenv:py27integration]
-basepython = python2.7
+[testenv:integration]
 commands = /bin/bash run_tests.sh -N --integration --selenium-headless {posargs}
 
 [testenv:eslint]
-basepython = python3
 passenv = *
 commands = nodeenv -p
            npm install
            /bin/bash run_tests.sh -N --eslint
 
 [testenv:docs]
-basepython = python3
 setenv = DJANGO_SETTINGS_MODULE=openstack_dashboard.test.settings
 commands = python setup.py build_sphinx