Debian : fix startup Docker 1.7 et kernel 4.1

sept. 20 19:34:19 muse systemd[1]: Started Docker Application Container Engine.
sept. 20 19:34:19 muse docker[18643]: time="2015-09-20T19:34:19.773439875+02:00" level=error msg="[graphdriver] prior storage driver \"aufs\" failed: driver not supported"
sept. 20 19:34:19 muse docker[18643]: time="2015-09-20T19:34:19.773487551+02:00" level=fatal msg="Error starting daemon: error initializing graphdriver: driver not supported"

# systemctl start docker