SPM support basic auth for non-git binary dependency hosts

[tomerd]

@mathaeus

I'm running into the same error that was reported in SPM support basic auth for non-git binary dependency hosts - #59 by tallariel

failed downloading 'https://api.github.com/repos/xxx/xxx/releases/assets/xxx.zip' which is required by binary target 'xxx': badResponseStatusCode(404)

I have read through most of the thread, but I'm still unsure: Will SPM support downloading private Github release assets with the next Xcode/Swift version? @tomerd

@mathaeus once we get a confirmation that the proposed solution in SPM support basic auth for non-git binary dependency hosts - #74 by tomerd is useful for folks, we can merge the after-mentioned PR which will also be included in the next schedule release of Xcode.