Add test `SHPC_degenerate`

To replace `Inst_eddies/Tests/Input/SHPC_degenerate`. The motivation
is to have the `cont_list` shapefile, so we can use it with
`test_set_max_speed`.

Inst_eddies/Tests/short_tests.json

@@ -255,6 +255,22 @@
 	],
 	"input": "t\n"
     },
+    "SHPC_degenerate":
+    {
+	"commands":
+	[
+            ["mkdir", "-p", "SHPC/Slice_0/Anticyclones"],
+	    [
+		"$build_dir/Inst_eddies/Tests/test_get_1_outerm",
+		"$src_dir/Inst_eddies/Tests/Input/degenerated_SSH.nc",
+		"$src_dir/Inst_eddies/Tests/Input/degenerated_SSH.nc"
+	    ]
+	],
+	"input":
+	"&MAIN_NML IND_TARG_EXTR = 5 3 INNERMOST_LEVEL = -1.2629 CYCLONE = f date = 15780/\n",
+	"create_file": ["config_nml.txt", "&config_nml /\n"],
+	"description": "This test is only useful to create input for test Set_max_speed_degenerate. Namelist values were obtained with test_local_extrema."
+    },
     "Set_max_speed_degenerate": {
 	"create_file": [
             "config_nml.txt",