Add tox file for local testing

Signed-off-by: Philippe Ombredanne <pombredanne@nexb.com>

Author: pombredanne

tox.ini

@@ -0,0 +1,10 @@
+[tox]
+envlist = py{27,36}
+
+[testenv]
+deps = pytest 
+ mock
+commands = {posargs:pytest} -vvs
+
+[pytest]
+testpaths = src tests/