Link to github and/or packagist

[matheus1lva]

Explanation

This PR creates a command so eve can answer with Packagist or/and Github repo URLs depending on what does the user requests.

For example:

@eve link me Illuminate\Log\Writer
Eve will answer:
https://github.com/illuminate/log/blob/1c05e0aa8fa7434a1981c5b36bb32b6ea3b0d1ff//Writer.php

@eve link me Illuminate\Log
Eve will answer :
https://github.com/illuminate/log

and more general:

@eve link me log
Eve will answer with all the possible urls.

Fixes #24 #10

[matheus1lva]

I just realize that if the user requests something like Illuminate\Auth\Access\Gate it won't work. I'm going to work to fix that.

[Riari]

Looks good so far 👍

[mdavis1982]

@playma256 Have you had a chance to have a look at this yet at all?

[matheus1lva]

@mdavis1982 not yet, i've being busy, but i will as soon as possible.