Add flake8 make task

Fix 'make test' task to run a complete series of tests
Signed-off-by: Joffrey F <joffrey@docker.com>

Makefile

@@ -13,7 +13,7 @@ build:
 build-py3:
 	docker build -t docker-py3 -f Dockerfile-py3 .
 
-test: unit-test integration-test unit-test-py3 integration-test-py3
+test: flake8 unit-test unit-test-py3 integration-dind
 
 unit-test: build
 	docker run docker-py py.test tests/test.py tests/utils_test.py
@@ -32,3 +32,6 @@ integration-dind: build build-py3
 	docker run --volumes-from dpy-dind --env="DOCKER_HOST=tcp://docker:2375" --link=dpy-dind:docker docker-py py.test -rxs tests/integration_test.py
 	docker run --volumes-from dpy-dind --env="DOCKER_HOST=tcp://docker:2375" --link=dpy-dind:docker docker-py3 py.test -rxs tests/integration_test.py
 	docker rm -vf dpy-dind
+
+flake8: build
+	docker run docker-py flake8 docker tests
\ No newline at end of file

test-requirements.txt

@@ -2,3 +2,4 @@ mock==1.0.1
 pytest==2.7.2
 coverage==3.7.1
 pytest-cov==2.1.0
+flake8==2.4.1
\ No newline at end of file