trying to prevent travis out of memory problems
trying to prevent travis out of memory problems

setting test jvm maximum memory to 2g
running only a single test jvm on travis

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