Release a Windows build

[giggio]

It would be cool if you would release Windows binaries, too.
I'm not a Gopher, but I believe you can cross compile it, right? I'm not sure how hard it would be.

[neurosnap]

Thanks for submitting this issue! I looked into seeing if our build worked by targeting windows and unfortunately there's at least one issue that is not straightforward:

cron/cron.go:73:41: unknown field 'Setpgid' in struct literal of type syscall.SysProcAttr

supercronic/cron/cron.go

Line 73 in 298ae31

cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}

I found a reference to this issue on GH but CreationFlags doesn't exist so I'm assuming there's more to this:

• https://stackoverflow.com/a/35435038
• https://stackoverflow.com/a/66500411

I'd be happy to accept a PR for supporting windows.