update docker version code example

Example 1: docker post installation steps linux

# Creates docker group
sudo groupadd docker

# Add your user to the docker group
sudo usermod -aG docker $USER

# Log out and log back in so that your group membership is re-evaluated
# GNOME example
gnome-session-quit

Example 2: install docker linux

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

Example 3: install docker ubuntu

$ sudo apt-get remove docker docker-engine docker.io containerd runc