Makefile: ignore failures on `sudo stop docker`
Makefile: ignore failures on `sudo stop docker`

It's fine if Docker isn't running.

paulbellamy/go-dockerclient,tarsisazevedo/go-dockerclient,csrwng/go-dockerclient,tarsisazevedo/go-dockerclient,ybogdanov/go-dockerclient,csrwng/go-dockerclient,davidstack/go-dockerclient,fsouza/go-dockerclient,ybogdanov/go-dockerclient,davidstack/go-dockerclient