add set e to gtfToCallingIntervals (#6)

gatk4-rna-best-practices.wdl

@@ -256,6 +256,9 @@ task gtfToCallingIntervals {
     Int preemptible_count
 
     command <<<
+
+	set -e
+
         Rscript --no-save -<<'RCODE'
             gtf = read.table("${gtf}", sep="\t")
             gtf = subset(gtf, V3 == "exon")