Set custom request headers

[greypants]

It'd be great to have a headers option you can pass in, like you can with [jQuery.ajax]. I need to pass along an auth token in Authorization header.

[LPology]

Thank you very much for this.

I just merged your PR, but there are a couple of changes I'm about to push. When looping through objects, it's good practice to use hasOwnProperty to distinguish between properties defined for the object and those inherited via the prototype:

    for ( var headerName in opts.customHeaders ) {
      if ( opts.customHeaders.hasOwnProperty( headerName ) ) {
        xhr.setRequestHeader( headerName, opts.customHeaders[headerName] );
      }
    }

[cillosis]

LPology, thank you for pointing out the hasOwnProperty method, I had not used it before but it makes sense now that I read about it, it makes sense! Thank you for pulling this into the library, now I can keep up with updates!

[LPology]

And thanks for your input. If you find anything else, please feel free to open an issue. I definitely appreciate it.

[greypants]

👍 Thanks guys!