Disable xenial in travis. Cannot check why tests fail
Disable xenial in travis. Cannot check why tests fail

ashish-gehani/OCCAM,SRI-CSL/OCCAM,SRI-CSL/OCCAM,ashish-gehani/OCCAM,SRI-CSL/OCCAM,ashish-gehani/OCCAM,ashish-gehani/OCCAM,SRI-CSL/OCCAM,SRI-CSL/OCCAM