Not calling RetryIfFunc when Attempt(0)

[ruijunwang]

From https://github.com/c1moore/retry-go/blob/063f78a88594e87168af0d800eac16839b533bcb/retry.go#L99, looks like the retryIf func is not called at all when attempt is set to 0, and I saw the same thing in my code. Is this intended or does it need to be fixed?

[simonhoss]

I have the same behavior and would expect that it retries as long as the RetryIf returns true

[JaSei]

I agree. It's a bug.

[merusso]

I wonder if this causes #83