Use default python for testing infrared plugin

This is because on CentOS ansible is not able to
be installed on provided python 3 because of missing
SE Linux python 3 byndings RPM

Change-Id: I252bc5d6f48cb12db2bb398bacf854d860823b8c

infrared-requirements.txt

@@ -0,0 +1 @@
+git+https://github.com/redhat-openstack/infrared.git  # Apache-2.0

tox.ini

@@ -177,10 +177,13 @@ commands = {posargs:bash}
 
 [testenv:infrared]
 
-# basepython = {[testenv:venv]basepython}
 # Package libselinux-python3 still not available on centos-7
-basepython = python3
-deps = {[testenv:venv]deps}
+basepython = python
+usedevelop = False
+skipdist = True
+skip_install = True
+deps =
+    -r infrared-requirements.txt
 passenv =
     {[testenv:venv]passenv}
     IR_*
@@ -189,11 +192,10 @@ setenv =
     IR_COMMAND={env:IR_COMMAND:{toxinidir}/tools/ci/ir}
     IR_HOME={env:IR_HOME:{envdir}/home/infrared}
 
-whitelist_externals = *
 commands =
-    bash -c '{env:IR_COMMAND} plugin remove tobiko || true'
-    {env:IR_COMMAND} plugin add {toxinidir}/roles
-    {env:IR_COMMAND} tobiko --tobiko-src-dir {toxinidir} {posargs}
+    -infrared plugin remove tobiko
+    ir plugin add {toxinidir}/roles
+    ir tobiko --tobiko-src-dir {toxinidir} {posargs}
 
 
 # --- documentation environments ----------------------------------------------