Add snack-bar message after renaming plan

src/app/degree-planner/store/effects/plan.effects.ts

@@ -187,6 +187,10 @@ export class DegreePlanEffects {
           map(() => {
             return new ChangePlanNameSuccess({ roadmapId, newName });
           }),
+          tap(() => {
+            const message = `Plan name has been changed to ${newName}`;
+            this.snackBar.open(message, undefined, {duration: 2000});
+          }),
           catchError(() => {
             return of(new ChangePlanNameFailure({ roadmapId, oldName }));
           }),