Remove Python 2.7 jobs

Ussuri release won't support Python 2.7 officially [1] so we can
drop CI jobs to test with Python 2.7.

[1] https://governance.openstack.org/tc/reference/runtimes/ussuri.html

Depends-On: https://review.opendev.org/688997
Change-Id: I650ca71c5a7c922a73f20cdf5ceb02caae464d02

.zuul.yaml

@@ -87,13 +87,6 @@
     irrelevant-files: *base_irrelevant_files
     vars: *base_vars
 
-- job:
-    name: horizon-dsvm-tempest-plugin-py27
-    parent: horizon-dsvm-tempest-plugin
-    vars:
-      devstack_localrc:
-        USE_PYTHON3: false
-
 - job:
     # Security testing for known issues
     name: horizon-tox-bandit-baseline
@@ -174,7 +167,6 @@
       - horizon-nodejs10-jobs
       - horizon-non-primary-django-jobs
       - openstack-lower-constraints-jobs
-      - openstack-python-jobs
       - openstack-python3-ussuri-jobs
       - periodic-stable-jobs
       - publish-openstack-docs-pti
@@ -184,14 +176,12 @@
         - horizon-selenium-headless
         - horizon-integration-tests
         - horizon-dsvm-tempest-plugin
-        - horizon-dsvm-tempest-plugin-py27
         - horizon-tox-bandit-baseline
         - horizon-tempest-plugin-ipv6
     gate:
       queue: horizon
       jobs:
         - horizon-dsvm-tempest-plugin
-        - horizon-dsvm-tempest-plugin-py27
         - horizon-selenium-headless
         - horizon-integration-tests
         - horizon-tempest-plugin-ipv6

setup.cfg

@@ -17,8 +17,6 @@ classifier =
     Operating System :: OS Independent
     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

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.1
-envlist = pep8,py27,py36,py37,py3-dj{111,21,22},releasenotes,npm
+envlist = pep8,py36,py37,py3-dj{111,21,22},releasenotes,npm
 skipsdist = True
 # Automatic envs (pyXX) will only use the python version appropriate to that
 # env and ignore basepython inherited from [testenv] if we set