Use stable Docker version on Ubuntu host.
@@ -91,7 +91,7 @@ EOF
apt-get -qqy install apt-transport-https ca-certificates
curl -sSL https://download.docker.com/linux/ubuntu/gpg | apt-key add -
- add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) test"
+ add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
apt-get -qqy update
apt-get -qqy install docker-ce
