Update Travis CI to use Ubuntu Xenial (#2808)
Update Travis CI to use Ubuntu Xenial (#2808)


gliljas/nhibernate-core,nhibernate/nhibernate-core,ngbrown/nhibernate-core,nhibernate/nhibernate-core,gliljas/nhibernate-core,fredericDelaporte/nhibernate-core,nhibernate/nhibernate-core,ngbrown/nhibernate-core,nhibernate/nhibernate-core,gliljas/nhibernate-core,fredericDelaporte/nhibernate-core,ngbrown/nhibernate-core,hazzik/nhibernate-core,fredericDelaporte/nhibernate-core,hazzik/nhibernate-core,gliljas/nhibernate-core,hazzik/nhibernate-core,hazzik/nhibernate-core,fredericDelaporte/nhibernate-core