ubuntu18.04 安装docker

https://docs.docker.com/install/linux/docker-ce/ubuntu/#install-docker-ce-1
Change "stable" repository to "edge" and works fine.

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04 LTS
Release:        18.04
Codename:       bionic

$ docker --version
Docker version 18.05.0-ce, build f150324