Stop testing python2.7

Train was the last release supporting python2. Let's rip the bandaid
off.

Change-Id: I5caf8d38f79dee0f80473b8f9b9c6664435aad88

setup.cfg

@@ -14,8 +14,6 @@ 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

@@ -1,10 +1,11 @@
 [tox]
 minversion = 2.0
-envlist = py27,py37,pep8
+envlist = py37,pep8
 skipsdist = True
 
 [testenv]
 usedevelop = True
+basepython = python3
 install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
@@ -15,15 +16,12 @@ deps =
 commands = stestr run --slowest {posargs}
 
 [testenv:pep8]
-basepython = python3
 commands = flake8
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [testenv:cover]
-basepython = python3
 setenv =
     PYTHON=coverage run --source os_net_config --parallel-mode
 commands =
@@ -34,7 +32,6 @@ commands =
 
 [testenv:docs]
 deps = -r{toxinidir}/doc/requirements.txt
-basepython = python3
 commands =
   sphinx-build -W -b html -d doc/build/doctrees doc/source doc/build/html
 

zuul.d/layout.yaml

@@ -2,7 +2,6 @@
     templates:
       - check-requirements
       - openstack-cover-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - publish-openstack-docs-pti
       - release-notes-jobs-python3