Python: bring back python 2.7 support for ansible 2.9 in supported EL distributions (#8192)

requirements-2.9.txt

@@ -4,5 +4,6 @@ netaddr==0.7.19
 pbr==5.4.4
 jmespath==0.9.5
 ruamel.yaml==0.16.10
-ruamel.yaml.clib==0.2.4
+ruamel.yaml.clib==0.2.4 ; python_version >= '3.5'
+ruamel.yaml.clib==0.2.2 ; python_version < '3.5'
 MarkupSafe==1.1.1

tests/requirements-2.9.txt

@@ -4,9 +4,12 @@ apache-libcloud==2.2.1
 tox==3.11.1
 dopy==0.3.7
 cryptography==2.8
-ansible-lint==5.0.11
+ansible-lint==5.0.11 ; python_version >= '3.0'
+ansible-lint==4.2.0 ; python_version < '3.0'
 openshift==0.8.8
-molecule==3.0.6
+molecule==3.0.6 ; python_version >= '3.0'
+molecule==3.0.2 ; python_version < '3.0'
 molecule-vagrant==0.3
-testinfra==5.2.2
+testinfra==5.2.2 ; python_version >= '3.0'
+testinfra==3.4.0 ; python_version < '3.0'
 python-vagrant==0.5.15