Add test `R4_15_splitted`

Overlap/Tests/short_tests.json

@@ -620,5 +620,15 @@
 	    ]
         ],
 	"input": "&main_nml cyclone = t, grid_lon_lat = f/\n"
+    },
+    {
+	"title": "R4_15_splitted",
+	"description": "This is not really a test. Rather it creates input necessary for tests.",
+	"env": {"PYTHONPATH": "$src_dir/Inst_eddies/Analysis"},
+	"command":
+	[
+	    "$src_dir/Overlap/Tests/split_SHPC.py",
+	    "$tests_old_dir/Region_4_15_days/SHPC"
+	]
     }
 ]