UPD: everything is better now :)

Makefile

@@ -1,17 +1,28 @@
 APPLICATION_NAME := django-test
-IMAGE_NAME := heinzel/$(APPLICATION_NAME)
+REPO_URL := https://heinzelwelt.de/vcs/python/django-test
+REPO_DIR := src/$(APPLICATION_NAME)
+IMAGE_NAME := $(APPLICATION_NAME)
 
 DOCKER := docker
+GIT    := git
 
-.PHONY: default help image run
+.PHONY: default help image test-run dist-clean
 
 default:	image
 
 help:
 	@echo "There is no help."
 
-image:
+$(REPO_DIR):
+	$(GIT) clone $(REPO_URL) $@
+
+$(IMAGE_NAME):	$(REPO_DIR)
 	$(DOCKER) build -t $(IMAGE_NAME) .
 
+image:		$(IMAGE_NAME)
+
 test-run:
 	$(DOCKER) run -ti --rm -p 80:80 $(IMAGE_NAME)
+
+dist-clean:
+	-rm -rf $(REPO_DIR)