Update Travis to Ubuntu 16.04 distro
Update Travis to Ubuntu 16.04 distro

Tisseo/navitia,Tisseo/navitia,Tisseo/navitia,patochectp/navitia,CanalTP/navitia,patochectp/navitia,Tisseo/navitia,patochectp/navitia,pbougue/navitia,xlqian/navitia,kinnou02/navitia,kinnou02/navitia,CanalTP/navitia,pbougue/navitia,patochectp/navitia,Tisseo/navitia,kinnou02/navitia,pbougue/navitia,CanalTP/navitia,CanalTP/navitia,xlqian/navitia,pbougue/navitia,CanalTP/navitia,xlqian/navitia,kinnou02/navitia,xlqian/navitia,xlqian/navitia