Move `Plot_eddy_contours_Mat` and `Stats_Matlab`

Move tests `Plot_eddy_contours_Mat` and `Stats_Matlab` to
`Convert_Matlab/Tests/long_tests.json`. Thus, we group the tests that
depend on the availability of Matlab.

Convert_Matlab/Tests/long_tests.json

@@ -23,5 +23,24 @@
 	    "$src_dir/Convert_Matlab/inst_eddies.m",
 	    "$src_dir/Convert_Matlab/Tests/node_id_param.json"
 	]
+    },
+    {
+	"title": "Plot_eddy_contours_Mat",
+	"description":
+	"plot_eddy_contours.py on a file coming from the Matlab program.",
+	"command":
+	[
+	    "$src_dir/Inst_eddies/Analysis/plot_eddy_contours.py",
+	    "$PWD/Mat_v6_to_shapefiles/SHPC_cyclo", "--save=png"
+	]
+    },
+    {
+	"title": "Stats_Matlab",
+	"description": "With an SHPC made from conversion of Matlab data.",
+	"command":
+	[
+	    "$src_dir/Inst_eddies/Analysis/stat.py",
+	    "$PWD/Inst_eddies_v6_global/SHPC_anti"
+	]
     }
 ]

Inst_eddies/Analysis/tests.json

@@ -17,16 +17,6 @@
 	    "$tests_old_dir/Region_6/SHPC_cyclo", "--light"
 	]
     },
-    {
-	"title": "Plot_eddy_contours_Mat",
-	"description":
-	"plot_eddy_contours.py on a file coming from the Matlab program.",
-	"command":
-	[
-	    "$src_dir/Inst_eddies/Analysis/plot_eddy_contours.py",
-	    "$tests_old_dir/Mat_v6_to_shapefiles/SHPC_cyclo", "--save=png"
-	]
-    },
     {
 	"title": "Eddy_dump",
 	"command":
@@ -105,15 +95,6 @@
 	    "$tests_old_dir/Inst_eddies_py/SHPC_anti"
 	]
     },
-    {
-	"title": "Stats_Matlab",
-	"description": "With an SHPC made from conversion of Matlab data.",
-	"command":
-	[
-	    "$src_dir/Inst_eddies/Analysis/stat.py",
-	    "$tests_old_dir/Inst_eddies_v6_global/SHPC_anti"
-	]
-    },
     {
 	"title": "Filter",
 	"command":