Expose Blitz.io load testing via hubot.

I've tweaked Hubot to load scripts from node modules. If you're using my fork then all you need to do is add hubot-script-blitz to the packages.json (once it gets added to the NPM registry) and then again to the hubot-scripts.json.

You will need to configure two environment variables:

• HUBOT_BLITZ_EMAIL - The email address of your account.
• HUBOT_BLITZ_API_KEY - The API Key for your Blitz.io account.

The usage right now is very simple:

Joe: hubot blitz me http://example.com
Hubot: from: virginia
duration: 0.1183
status: 301
connect: 0.104818

More the API will get leveraged and commands will become richer.