Fix send_notification command to sendNotification

In the latest version of watchbot I'm proposing: https://github.com/hybridgroup/watchbot/pull/19

I've get rid of the commands configuration (I think it is simpler and clear for users), since a lot of thins are already happening....

So for a framework/robot to work with watchbot it must have a /publish_event and and /pending_message endpoints. Currently cylon only converts the command name to an url, so I know having a command 'publish_event' is not optimal, but having an endpoint /publishEvent isn't also.

In this case I prefer having the command names like that since also those commands are not intended for direct use by users, so having them in different format could be another point to discourage use.