Misuse of resolve/reject causes "close of closed channel" panic

[yoavsv]

Hello,

If I run:

mo.NewFuture(func(resolve func(struct{}), reject func(error)) {
    resolve(struct{}{})
    reject(errors.New("oh no..."))
})

I get panic: close of closed channel.

This makes me write defensive code (e.g. return after each call to reject / resolve). I would suggest to recover from panics and reflect it as an error as part of Result[T]'s error.