Update release notes.
Update release notes.

fscheck/FsCheck,ErikSchierboom/FsCheck,cloudRoutine/FsCheck,cloudRoutine/FsCheck,sideeffffect/FsCheck,fsharp/FsCheck,paulyoung/FsCheck,ploeh/FsCheck,paulyoung/FsCheck,jhamm/FsCheck,fscheck/FsCheck