Overload classes for both platforms

[iamtraction]

Export a class from cleverbot.js that'll allow to use cleverbot.com & cleverbot.io without any changes. It'll be seamless on the side of the developer using the library.

How can this be done?
Current idea is to check if APIUser is passed with the option. If it is, then it's cleverbot.io otherwise, cleverbot.com, because cleverbot.com doesn't need APIUser.
Another idea is to pass a new property with the option that'll distinguish if cleverbot.io or cleverbot.com should be used, but this won't be as seamless as the previous one.