Make a working gather step

Former-commit-id: f617d0b1

test_scatter/scatter-workflow.cwl

@@ -10,16 +10,10 @@ inputs:
 outputs:
   - id: output
     outputSource:
-      - cat/output
+      - cat_2/output
     type: File
-    'sbg:x': 549
-    'sbg:y': 14
-  - id: output_1
-    outputSource:
-      - cat_1/output
-    type: File
-    'sbg:x': 626.203125
-    'sbg:y': 204
+    'sbg:x': 778.4581909179688
+    'sbg:y': 95.88174438476562
 steps:
   - id: echo
     in:
@@ -65,5 +59,18 @@ steps:
     label: cat
     'sbg:x': 454.203125
     'sbg:y': 219
+  - id: cat_2
+    in:
+      - id: files
+        source:
+          - cat/output
+          - cat_1/output
+    out:
+      - id: output
+    run: ./cat.cwl
+    label: cat
+    'sbg:x': 648.4573364257812
+    'sbg:y': 104.00638580322266
 requirements:
   - class: ScatterFeatureRequirement
+  - class: MultipleInputFeatureRequirement