Remove MANIFEST with make clean

Signed-off-by: Christian Heimes <cheimes@redhat.com>

Makefile

@@ -10,7 +10,7 @@ all:
 
 .PHONY: clean
 clean:
-	rm -rf build dist *.egg-info $(VENV) .tox
+	rm -rf build dist *.egg-info $(VENV) .tox MANIFEST
 	rm -f .coverage .coverage.*
 	find . -name '*.py[co]' -or -name '*.so*' -or -name '*.dylib' -delete
 	find . -depth -name __pycache__ -exec rm -rf {} \;