Implement triggering weather function from robot.emit

Made changes so you could trigger weather from a script like below;
<pre>
<code>
module.exports = (robot) ->
  robot.respond /(weather)?/i, (msg) ->
    text = msg.message.text
    if text.match(/weather/i)
	    robot.emit "weather", msg, { city : "Melbourne" } // User need to figure out the logic to pull city from the msg
</code>
</pre>