add --no-cache option to docker build

Change-Id: I5e9bbcebaa120d79db04819bfdfb28c5f5261012
diff --git a/Makefile b/Makefile
index f640ab8..3d4c5bb 100644
--- a/Makefile
+++ b/Makefile
@@ -55,6 +55,7 @@
 	--build-arg REPOSITORY=$(REPOSITORY) \
 	$(DOCKER_PROXY_ARGS) $(DOCKER_CACHE_ARG) \
 	 --rm --force-rm \
+	 --no-cache \
 	$(DOCKER_BUILD_EXTRA_ARGS)
 
 VENVDIR := venv-$(shell uname -s | tr '[:upper:]' '[:lower:]')