Link to actual Github Contributors

[raulraja]

The following PR updates the AUTHORS file to include a link to the Github contributors list and charts which is automatically kept up to date.

@ceedubs @adelbertc @non Thanks for considering it.

[aryairani]

I like the existing version better :-\ But maybe it's too much work to maintain?

[raulraja]

For reference here is the link to the comment that triggered this PR https://gitter.im/non/cats?at=569afe4759e3d04215bc2fc4
I'm fine if folks would rather maintain a manual list though PR authors won't update it and the list will become obsolete in no time given the fast pace in which Cats is evolving.

[codecov-io]

Current coverage is 89.11%

Merging #815 into master will not affect coverage as of 0dc8f98

@@            master    #815   diff @@
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  Files          168     168       
  Stmts         2306    2306       
  Branches        75      75       
  Methods          0       0       
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  Hit           2055    2055       
  Partial          0       0       
  Missed         251     251       

Review entire Coverage Diff as of 0dc8f98

Powered by Codecov. Updated on successful CI builds.

[ceedubs]

Thanks @raulraja. To me, there is some appeal of a manually curated list, because it seems more personal (I'm guessing this is where @refried is coming from). However, I do agree that it will constantly slip out of date, which is probably worse than not having the list at all. @non do you want to weigh in on this?

If we take this approach, what do you think about changing it to something like this?

Thank you to [the contributors](https://github.com/non/cats/graphs/contributors) whose work has made Cats possible

Also: this PR currently has a merge conflict.

[raulraja]

@non @ceedubs I'm happy with a manual approach as well, just added this since it seem like people liked the way Ensime handled it but I understand that the link is a bit of indirection and not as personable. I'm gonna close sit since it looks like there are mixed feelings and people are not convinced this is what is best for Cats. Feel free to reopen or do whatever. Thanks for your consideration :)