Add capitalization in messages

Currently, all messages are taken `toLowerCase()` and returned as `query` in [recieveMessage](https://github.com/92Eli/rbot/blob/master/receiveMessage.js). When setting the reminder message, though, capitalization should remain intact.
We must make sure that if we do not make `query` lowercase beforehand, we do that before passing to other functions (like `setTimeOrDay`).