Added support for running in the browser

[DoryZi]

Hi,

Great project! I've started to use it. However the missing browser module, wasn't super trivial so I created a browser port of this swagger npm module. Here it is: https://github.com/CoreTeamIO/js-browser-flagr

would be cool to be included in your readme, if that makes sense to you. I just want to help people use this easily.

Cheers D.