Drop py2 testing and metadata

This drops testing of py2 environments and removes it from the package
metadata.

Story: #2003229
Task: #23646

Change-Id: Ieb6ed753705aa5f35e58ec4f3796b4ad9e5e33c3
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

.gitignore

@@ -8,6 +8,7 @@ results
 
 # Packages
 *.egg
+*.eggs
 *.egg-info
 dist
 build

.zuul.yaml

@@ -1,5 +1,4 @@
 - project:
     templates:
-      - openstack-python-jobs-no-constraints
       - openstack-python37-jobs-no-constraints
       - publish-openstack-docs-pti

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 :: 3.7
 

tox.ini

@@ -1,10 +1,14 @@
 [tox]
-minversion = 1.6
+minversion = 3.1.0
-envlist = py27,py35,pep8,docs
+envlist = py3,pep8,docs
 skipsdist = True
+# this allows tox to infer the base python from the environment name
+# and override any basepython configured in this file
+ignore_basepython_conflict=true
 
 [testenv]
 usedevelop = True
+basepython = python3
 install_command = pip install -U {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
@@ -13,7 +17,6 @@ deps = -r{toxinidir}/requirements.txt
 commands = stestr run --slowest {posargs}
 
 [testenv:docs]
-basepython = python3
 deps = -r{toxinidir}/doc/requirements.txt
 commands = sphinx-build -W -b html -d doc/build/doctrees doc/source doc/build/html