VOL-1688 Fixing subtle error where multiple dist versions can exist if the version file is updated without a make clean. This can cause the wrong version to be loaded in local builds

Change-Id: I18ee71fa6875aae70ace6c9861926c4b3b43644b
diff --git a/Makefile b/Makefile
index a0f1ad6..45690aa 100644
--- a/Makefile
+++ b/Makefile
@@ -77,6 +77,7 @@
     $<
 
 python-build: setup.py python-protos
+	rm -r dist/
 	python ./setup.py sdist
 
 python-test: tox.ini setup.py python-protos