update build.sbt with correct version of wdl4s
update build.sbt with correct version of wdl4s

ohsu-comp-bio/cromwell,broadinstitute/cromwell,broadinstitute/cromwell,ohsu-comp-bio/cromwell,ohsu-comp-bio/cromwell,broadinstitute/cromwell,broadinstitute/cromwell,broadinstitute/cromwell