Make a release

[ndmitchell]

For Windows users, being able to download a release of fsatrace would be very handy, as compiling requires a bunch of things most Windows users don't have. I'm happy to generate the binary and share, but the GitHub releases page of this repo is the most natural place to host them.

[jacereda]

I guess the right thing would be to make AppVeyor deploy the release automatically. I found this guide, might try it when I have some time (probably next week).

https://www.appveyor.com/docs/deployment/github/