Porting fsirc project to F# ProjectScaffold setup.

I have created version of fsirc project using [F# ProjectScaffold](https://github.com/fsprojects/ProjectScaffold). It has files/ folders layout and tooling recommended and popular in F# comunnity such as [FAKE](https://github.com/fsharp/FAKE) build system and [Paket](https://github.com/fsprojects/Paket) package dependency manager