Some minor fixes

We've started running this ourselves at Librato for our new Slack channels. Thanks for putting it together, looks like a good start. I found a few issues that caused it to not work for us. Not sure if you're still running it but I expect we'll continue to enhance it under my fork.

I had to remove `scripts` from `scriptsPath` in `index.coffee` or Hubot refused to import it. I tweaked the regex for whitespace so you can query with just `graph me foo`. Otherwise it wouldn't run without at least one whitespace character following the graph string. Lastly, the `reduce` was failing since `instruments` is not nested under `query` in the API response.