BaseSpace run_id patch (#8)

Fixes #7 

* Ensure run_id is captured

* fix syntax

* check run id variable

workflows/wf_basespace_fetch.wdl

@@ -47,7 +47,13 @@ task fetch_bs {
 
     #Grab BaseSpace Run_ID from given BaseSpace Run Name
     run_id=$(${bs_command} list run | grep "~{basespace_run_name}" | awk -F "|" '{ print $3 }' | awk '{$1=$1;print}' )
-    echo "run_id: ${run_id}"
+    echo "run_id: ${run_id}" 
+
+    if [[ -z "${run_id}" ]]
+    then 
+      echo "No run id found associated with input BaseSpace run name: ~{basespace_run_name}" >&2
+      exit 1
+    fi
 
     #Grab BaseSpace Dataset ID from dataset lists within given run 
     dataset_id_array=($(${bs_command} list dataset --input-run=${run_id} | grep "~{dataset_name}" | awk -F "|" '{ print $3 }' ))