Removed python 2.7 test triggers

Python 2.7 is no longer supported.
Removed its zull and tox tests.

Test Plan:
PASS build-pkgs

Story: 2010531
Task: 47512

Signed-off-by: Leonardo Fagundes Luz Serrano <Leonardo.FagundesLuzSerrano@windriver.com>
Change-Id: I34ac268dd834e272fdc26d1efb0895f19ef17491

.zuul.yaml

@@ -5,7 +5,6 @@
     check:
       jobs:
         - openstack-tox-linters
-        - k8sapp-auditd-tox-py27
         - k8sapp-auditd-tox-py39
         - k8sapp-auditd-tox-flake8
         - k8sapp-auditd-tox-pylint
@@ -13,29 +12,11 @@
     gate:
       jobs:
         - openstack-tox-linters
-        - k8sapp-auditd-tox-py27
         - k8sapp-auditd-tox-py39
         - k8sapp-auditd-tox-flake8
         - k8sapp-auditd-tox-pylint
         - k8sapp-auditd-tox-bandit
 
-- job:
-    name: k8sapp-auditd-tox-py27
-    parent: tox
-    description: |
-            Run py27 test for k8sapp_auditd
-    nodeset: ubuntu-bionic
-    required-projects:
-      - starlingx/config
-      - starlingx/fault
-      - starlingx/update
-      - starlingx/utilities
-    files:
-      - python-k8sapp-auditd/*
-    vars:
-      tox_envlist: py27
-      tox_extra_args: -c python-k8sapp-auditd/k8sapp_auditd/tox.ini
-
 - job:
     name: k8sapp-auditd-tox-py39
     parent: tox-py39

python-k8sapp-auditd/k8sapp_auditd/setup.cfg

@@ -14,8 +14,6 @@ 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 :: 3.4
     Programming Language :: Python :: 3.5

python-k8sapp-auditd/k8sapp_auditd/tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = flake8,py27,py36,py39,pylint,bandit
+envlist = flake8,py36,py39,pylint,bandit
 minversion = 1.6
 
 # tox does not work if the path to the workdir is too long, so move it to /tmp
@@ -66,13 +66,6 @@ deps = -r{toxinidir}/test-requirements.txt
 commands =
   flake8 {posargs} .
 
-[testenv:py27]
-basepython = python2.7
-commands =
-  {[testenv]commands}
-  stestr run {posargs}
-  stestr slowest
-
 [testenv:py36]
 basepython = python3.6
 commands =
@@ -121,7 +114,7 @@ commands =
      pylint {posargs} k8sapp_auditd --rcfile=./pylint.rc
 
 [testenv:cover]
-basepython = python2.7
+basepython = python3
 deps = {[testenv]deps}
 setenv = {[testenv]setenv}
          PYTHON=coverage run --parallel-mode