Cleanup before build

Makefile

@@ -5,7 +5,11 @@ TAG=arkindex-backend
 
 .PHONY: build
 
-build:
+clean:
+	rm -rf *.egg-info build dist .eggs
+	find . -name '*.pyc' -exec rm {} \;
+
+build: clean
 	docker build $(ROOT_DIR) -t $(TAG):$(VERSION)
 
 publish-version: require-docker-auth