Add test `Traj_component`

Trajectories/Tests/tests.json

@@ -177,5 +177,14 @@
             "$tests_old_dir/Cost_function_no_debug/segments_cost_functions.graphml",
             "segments.gv"
 	]
+    },
+    "Traj_component":
+    {
+	"description": "Recompute trajectories on an extracted component.",
+	"command":
+	[
+	    "$src_dir/Trajectories/trajectories.py",
+	    "$tests_old_dir/Extract_component/component_1980897.graphml"
+	]
     }
 }