Support TESTFLAGS

Makefile

@@ -8,7 +8,7 @@ doc:
 	cd docs && docker build -t docker-docs . && docker run -p 8000:8000 docker-docs
 
 test: bundles
-	docker run -privileged -v `pwd`/bundles:/go/src/github.com/dotcloud/docker/bundles docker hack/make.sh test
+	docker run -e TESTFLAGS -privileged -v `pwd`/bundles:/go/src/github.com/dotcloud/docker/bundles docker hack/make.sh test
 
 shell:
 	docker run -privileged -i -t docker bash