Update wiki for Ubuntu 16.04 LTS

[ariyanmorshed]

Hello, I was trying to setup Revelin into Ubuntu 16 but I find Only Ubntu 14 source are available into source

#Ravelin on Launchpad
deb http://ppa.launchpad.net/gwu-positronics/ravelin/ubuntu trusty main
deb-src http://ppa.launchpad.net/gwu-positronics/ravelin/ubuntu trusty main

please update wiki for UBuntu 16