Drop python 2.7 support and testing

Ussuri Communtiy-wide goal:
https://governance.openstack.org/tc/goals/selected/ussuri/drop-py27.html

Change-Id: I53daab51cc782e878658566b9ac91d134173ce21

setup.cfg

@@ -15,8 +15,6 @@ classifier =
 	License :: OSI Approved :: Apache Software License
 	Operating System :: OS Independent
 	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]
 minversion = 2.0
 skipsdist = True
-envlist = py27,py37,pep8
+envlist = py37,pep8
 
 [testenv]
+basepython = python3
 usedevelop = True
 install_command = pip install {opts} {packages}
 deps =
@@ -17,11 +18,9 @@ commands =
 sitepackages = True
 
 [testenv:pep8]
-basepython = python3
 commands = flake8
 
 [testenv:cover]
-basepython = python3
 setenv =
     PYTHON=coverage run --source os_apply_config --parallel-mode
 commands =
@@ -31,7 +30,6 @@ commands =
     coverage xml -o cover/coverage.xml
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [flake8]
@@ -39,7 +37,6 @@ exclude = .venv,.tox,dist,doc,*.egg
 show-source = true
 
 [testenv:lower-constraints]
-basepython = python3
 deps =
   -c{toxinidir}/lower-constraints.txt
   -r{toxinidir}/test-requirements.txt

zuul.d/layout.yaml

@@ -3,6 +3,5 @@
       - check-requirements
       - openstack-cover-jobs
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - tripleo-multinode-container-minimal