install docker-machine in ubuntu code example

Example 1: install docker ubuntu

$ curl -fsSL https://get.docker.com -o get-docker.sh
$ sudo sh get-docker.sh

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Example 2: install docker linux

sudo apt-get install -y linux-image-generic-lts-trusty linux-headers-generic-lts-trusty

Example 3: docker ubuntu installation

$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -