Update Gentrap test for compatibility with new reference

public/gentrap/src/test/scala/nl/lumc/sasc/biopet/pipelines/gentrap/GentrapTest.scala

@@ -197,8 +197,8 @@ object GentrapTest {
   copyFile("ref.fa.fai")
 
   val executables = Map(
+    "reference" -> (outputDir + File.separator + "ref.fa"),
     "reference_fasta" -> (outputDir + File.separator + "ref.fa"),
-    "dict" -> "test",
     "refFlat" -> "test",
     "annotation_gtf" -> "test",
     "annotation_bed" -> "test",