Promote obmc.mapper to python package

Enable additional modules in the mapper package namespace.

Change-Id: If2b38eef13b194a6087bb80947884f94bb2a5881
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/setup.py b/setup.py
index 9f704fd..9967f98 100644
--- a/setup.py
+++ b/setup.py
@@ -1,6 +1,6 @@
 from distutils.core import setup
 setup(name='phosphor-mapper',
       version='1.0',
-      py_modules=['obmc.mapper'],
+      packages=['obmc.mapper'],
       scripts=['phosphor-mapper']
       )