Library ported to Go

Hi,

Just to let folk know that I have ported this library from its original C++ into Go.

https://github.com/jimsmart/grobotstxt

My conversion includes 100% of the original library's functionality, and 100% of the tests.

Because I approached this conversion function-by-function, some of the resulting code is not necessarily idiomatic Go — but, in places, I have made some cleanups, including renaming a few things.

But otherwise my package is a faithful reproduction of the code in this here repo.

I have licensed my code with Apache 2.0, as per this repo, and I have preserved existing copyright notices and licensing within the appropriate source files.

— Regarding this last matter, as my code is technically a derivative of this repo's code, would someone here please care to check my project with regards to the above-mentioned licensing requirements, to ensure that what I have done is correct? Many thanks.

/Jim