Update tox.ini inline with other interfaces

Resync tox.ini file with other reactive interfaces to ensure a
consistent approach to tox targets.

Change-Id: I8736fd8229e3a3343eb1096a0f115e8ae5544211

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = lint,py34,py35
+envlist = pep8,py27,py34,py35
 skipsdist = True
 skip_missing_interpreters = True
 
@@ -10,13 +10,23 @@ install_command =
   pip install {opts} {packages}
 commands = ostestr {posargs}
 
+[testenv:py27]
+basepython = python2.7
+deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
+
 [testenv:py34]
 basepython = python3.4
 deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
 
 [testenv:py35]
 basepython = python3.5
 deps = -r{toxinidir}/test-requirements.txt
+# TODO: Need to write unit tests then remove the following command.
+commands = /bin/true
 
 [testenv:pep8]
 basepython = python2.7