Fix authorship

Hi!

I noticed that a not-insignificant amount of the code in web-console is derived from my [better_errors](https://github.com/charliesome/better_errors) project, which (like web-console) is published under the MIT license. I'm totally ok with that code being used in web-console - after all, the reason I chose the MIT license is that I believe that if others find my code useful, they should be free to take it and use it in their own projects.

That said, I spent quite a bit of my own time developing and debugging the code in better_errors, and I would appreciate some attribution for that work. While the MIT license is fairly liberal in what it permits, one of its conditions is that the license (including copyright notice) remains intact in works making use of MIT licensed code.

To sort this out, I've opened this PR which adds my name to the copyright notice and the gem author list. That's all I ask.

Cheers :)