It seems like docker was already installed on the machine with a newer version and the script tried to downgrade the docker version and failed.
1. Please try to remove the docker with the following command:
apt-get purge docker-engine
2. Please try to run the ship installation script again.
Regarding the "NO MORE HOSTS LEFT" - this is a message from Ansible saying it can't finish the job on this host due to the above failure, it is trying to move on to the next host but there is no more hosts on the list so it displays NO MORE HOSTS LEFT. This has nothing to do with the number of ships you are allowed to install.