Save the figure in the test

Trajectories/Tests/tests.json

@@ -116,7 +116,7 @@
 	    "$tests_old_dir/Trajectories/expanded_traj.json",
 	    "$tests_old_dir/Cost_functions/e_overestim.txt",
 	    "$tests_old_dir/Extraction_eddies_region_2_noise/SHPC",
-	    "Anticyclones"
+	    "Anticyclones", "--save=png"
 	]
     }
 ]