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

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

senlin-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: Ib279cb1d0820ef6e9a07079ccd2bb7768b5f5967

.zuul.yaml

@@ -4,7 +4,6 @@
       - horizon-non-primary-django-jobs
       - horizon-nodejs10-jobs
       - openstack-lower-constraints-jobs-horizon
-      - openstack-python-jobs-horizon
       - openstack-python3-ussuri-jobs-horizon
       - publish-openstack-docs-pti
       - release-notes-jobs-python3

doc/requirements.txt

@@ -11,5 +11,4 @@ mock>=2.0.0 # BSD
 openstackdocstheme>=1.18.1 # Apache-2.0
 reno>=2.5.0 # Apache-2.0
 sphinxcontrib-apidoc>=0.2.0  # BSD
-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

releasenotes/notes/drop-py-2-7-f8879b776d5781a8.yaml

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

setup.cfg

@@ -5,8 +5,6 @@ description-file = README.rst
 license = Apache License, Version 2.0
 classifiers =
     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 +1,10 @@
 [tox]
-envlist = py37,pep8,py27-local,py36-local,py3-{dj111,dj22},eslint,karma-local,docs-local,releasenotes,lower-constraints-local
+envlist = py37,pep8,,py36-local,py3-{dj111,dj22},eslint,karma-local,docs-local,releasenotes,lower-constraints-local
 minversion = 2.3.2
 skipsdist = True
 
 [testenv]
+basepython = python3
 usedevelop = True
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
@@ -21,11 +22,9 @@ commands =
   pip install -e ../horizon
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:pep8]
-basepython = python3
 commands = flake8
 
 [flake8]
@@ -37,18 +36,11 @@ enable-extensions = H203,H106
 exclude=.venv,.git,.tox,dist,doc,*lib/python*,*egg,build,.ropeproject,tools,node_modules
 
 [testenv:cover]
-basepython = python3
 commands = python setup.py testr --coverage --testr-args='{posargs}'
 
 # NOTE(shu-mutow): On CI infra, horizon will be installed
 # according to job setting. but on local, we need to install
 # horizon from master branch.
-[testenv:py27-local]
-basepython = python2.7
-commands =
-  {[testenv:hz-local]commands}
-  {[testenv]commands}
-
 [testenv:py36-local]
 basepython = python3.6
 commands =
@@ -56,7 +48,6 @@ commands =
   {[testenv]commands}
 
 [testenv:eslint]
-basepython = python3
 whitelist_externals =
   npm
 commands =
@@ -67,7 +58,6 @@ commands =
 # from master branch into py35 environment for testing javascripts.
 # Horizon from master is needed to be cloned into ../horizon on both local and CI.
 [testenv:karma]
-basepython = python3
 whitelist_externals =
   {[testenv:eslint]whitelist_externals}
 commands =
@@ -75,14 +65,12 @@ commands =
   npm run test
 
 [testenv:karma-local]
-basepython = python3
 whitelist_externals =
   {[testenv:eslint]whitelist_externals}
 commands =
   {[testenv:karma]commands}
 
 [testenv:docs]
-basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://releases.openstack.org/constraints/upper/master}
   -r{toxinidir}/doc/requirements.txt
@@ -90,7 +78,6 @@ commands=
   sphinx-build -W -b html doc/source doc/build/html
 
 [testenv:docs-local]
-basepython = python3
 deps =
   {[testenv:docs]deps}
 commands=
@@ -98,33 +85,28 @@ commands=
   {[testenv:docs]commands}
 
 [testenv:releasenotes]
-basepython = python3
 deps =
   {[testenv:docs]deps}
 commands =
   sphinx-build -a -E -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 
 [testenv:debug]
-basepython = python3
 whitelist_externals = oslo_debug_helper
 commands = oslo_debug_helper -t senlin_dashboard/test {posargs}
 
 [testenv:makemessages]
-basepython = python3
 commands =
     pybabel extract -F babel-django.cfg -o senlin_dashboard/locale/django.pot -k gettext_noop -k gettext_lazy -k ngettext_lazy:1,2 -k ugettext_noop -k ugettext_lazy -k ungettext_lazy:1,2 -k npgettext:1c,2,3 -k pgettext_lazy:1c,2 -k npgettext_lazy:1c,2,3 senlin_dashboard
     pybabel extract -F babel-djangojs.cfg -o senlin_dashboard/locale/djangojs.pot -k gettext_noop -k gettext_lazy -k ngettext_lazy:1,2 -k ugettext_noop -k ugettext_lazy -k ungettext_lazy:1,2 -k npgettext:1c,2,3 -k pgettext_lazy:1c,2 -k npgettext_lazy:1c,2,3 senlin_dashboard
 
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt
   -r{toxinidir}/requirements.txt
 
 [testenv:lower-constraints-local]
-basepython = python3
 deps =
   {[testenv:lower-constraints]deps}
 commands =