HSD testing update for Hercules

Author: Natalie Perlin

tests/compile.sh

@@ -63,7 +63,10 @@ case ${MACHINE_ID} in
     # Activate lua environment for gaea c5
     if [[ ${MACHINE_ID} == gaea ]]; then
       module reset
+    elif [[ ${MACHINE_ID} == hercules ]]; then
+      module purge
     fi
+
     # Load fv3 module
     module use "${PATHTR}/modulefiles"
     modulefile="ufs_${MACHINE_ID}.${RT_COMPILER}"