travis tweaks for 4.0 branch.
travis tweaks for 4.0 branch.

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