moving to sudo enabled travis
moving to sudo enabled travis

travis support recommended that we move to travis with sudo since the capacity problems have been fixed
the travis nodes with sudo are more powerful now and there shouldn't be long startup delays like there used to be
also moving to the newer ubuntu image

ksthesis/gatk,broadinstitute/hellbender,ksthesis/gatk,ksthesis/gatk,frank-y-liu/gatk,magicDGS/gatk,broadinstitute/hellbender,magicDGS/gatk,frank-y-liu/gatk,broadinstitute/hellbender,ksthesis/gatk,frank-y-liu/gatk,magicDGS/gatk,broadinstitute/hellbender,magicDGS/gatk,ksthesis/gatk,magicDGS/gatk,ksthesis/gatk,broadinstitute/hellbender,magicDGS/gatk,frank-y-liu/gatk,frank-y-liu/gatk,broadinstitute/hellbender,frank-y-liu/gatk