change learning object like method comment

app/repositories/orient_db/learning_object_repository.rb

@@ -9,7 +9,7 @@ module OrientDb
 
     #
     # Usage:
-    #   repository.for(:learning_objects).like @learning_object, current_user
+    #   repository.for(:learning_objects).like current_user, @learning_object
     #
     def like(user, learning_object)
       create_edge "Likes", user.rid, learning_object.id