Remove unneeded items from Makefile

Remove env sourcing as a requirement.
Also fix base image naming bug.

Change-Id: I7e62b47853562015e7731ea199eb24d80976f065
diff --git a/python/env.sh b/python/env.sh
index 433b975..ac26835 100644
--- a/python/env.sh
+++ b/python/env.sh
@@ -25,5 +25,5 @@
 fi
 . $VENVDIR/bin/activate
 
- #add top-level voltha dir to pythonpath
+#add top-level voltha dir to pythonpath
 export PYTHONPATH=$VOLTHA_BASE/$VENVDIR/lib/python2.7/site-packages:$PYTHONPATH:$VOLTHA_BASE:$VOLTHA_BASE/cli:$VOLTHA_BASE/protos/third_party