Add Coverity stuff back in Travis script and remove Clang build to try and solve issues with building coverage analysis conditionally only for GCC.
Add Coverity stuff back in Travis script and remove Clang build to try and solve issues with building coverage analysis conditionally only for GCC.

openastro/sml,astropnp/sml,Stardust2013/sml,kartikkumar/sml,ennehekma/sml,ennehekma/sml,Stardust2013/sml,astropnp/sml