Travis-CI: Use 'set -e' to exit on first error
Travis-CI: Use 'set -e' to exit on first error

Travis-CI will report running a script as a success as long as
the last command in a script has a zero exit status.

The build should fail if any commands have a non-zero
exit status. This should fix the problem.

Signed-off-by: Patrick Avery <9998cd7370de5e06514e1c73829a1fbd24ae8b10@buffalo.edu>

OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs,OpenChemistry/avogadrolibs,ghutchis/avogadrolibs