Change DNS on Ubuntu

In /etc/NetworkManager/NetworkManager.conf comment out the line dns=dnsmasq

sudo nano /etc/NetworkManager/NetworkManager.conf
[main]
plugins=ifupdown,keyfile,ofono
#dns=dnsmasq

and restart the NetworkManager service.

sudo restart network-manager

sudo rm -f /etc/resolv.conf # Delete the symbolic link
sudo nano /etc/resolv.conf # Create static file

# Content of static resolv.conf
nameserver 208.67.220.220
nameserver 208.67.220.222

References
http://askubuntu.com/questions/690511/how-to-change-dns-in-ubuntu-15-10