Add simple tox.ini to make gate working

Change-Id: I9f487d504f3bcff8e12783b2e5f46ad551a30b51

tox.ini

@@ -0,0 +1,19 @@
+[tox]
+envlist = pep8
+minversion = 1.6
+skipsdist = True
+
+[testenv]
+usedevelop = True
+install_command = pip install -U {opts} {packages}
+setenv =
+    VIRTUAL_ENV={envdir}
+
+[tox:jenkins]
+downloadcache = ~/cache/pip
+
+[testenv:pep8]
+#commands = flake8 {posargs}
+
+[testenv:venv]
+commands = {posargs}