install Docker version (instead of Ubuntu version) of docker (docker-ce and not docker.io)

install-docker-ce.sh

#/bin/bash
# install packages to allow apt to use a repository over HTTPS:
sudo apt-get -y install \
apt-transport-https ca-certificates curl software-properties-common
# add Docker’s official GPG key:
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - 
# set up the Docker stable repository.
sudo add-apt-repository \
   "deb [arch=amd64] https://download.docker.com/linux/ubuntu \
   $(lsb_release -cs) \
   stable"
# update the apt package index:
sudo apt-get -y update
# finally, install docker
sudo apt-get -y install docker-ce