Do not require Docker 1.9 anymore
This was done when docker_build was not supporting the new OCI format
but it has long be done and prevent switching to the new docker_build
repo.
@@ -9,7 +9,7 @@ echo "deb https://apt.dockerproject.org/repo ubuntu-wily main" >/etc/apt/sources
apt-get -y update
# Installing docker might fails because the docker socket is masked.
# See https://github.com/docker/docker/issues/22847
-apt-get -y install docker-engine=1.9.* \
+apt-get -y install docker-engine \
|| (systemctl unmask docker.socket; service docker start; apt-get install -f)
# Docker group
