Add a basic script for querying Sourcing.io's API

This script allows Hubot to query the [sourcing.io API](https://sourcing.io/api).

For example, `hubot sourcing --twitter @alec_sloman` returns this message:

```
Alec Sloman
      Technical Recruiter at Lookahead Search
      located: Melbourne VIC, Australia
      languages: Not Coffeescript
      email: alec@lookahead.com.au
      score: 7.9
```

You can also search by `--email` address and `--github` username.

Ping @andrewk @xyfer - plz2 fix codes and implement all missing features. kthx

/cc @maccman your app only gave me a **7.9**. There is obviously something wrong with your algorithm.