Make group deleted text consistent with group created and updated texts

app/controllers/groups_controller.rb

@@ -88,7 +88,7 @@ class GroupsController < Groups::ApplicationController
   def destroy
     DestroyGroupService.new(@group, current_user).execute
 
-    redirect_to root_path, alert: "Group '#{@group.name}' was deleted."
+    redirect_to root_path, alert: "Group '#{@group.name}' was successfully deleted."
   end
 
   protected