Warning on 'sprintf' while compiling.

[ernestguillem]

While compiling picotool with macOS I get the following warning:
warning: 'sprintf' is deprecated: This function is provided for compatibility reasons only. Due to security concerns inherent in the design of sprintf(3), it is highly recommended that you use snprintf(3) instead. [-Wdeprecated-declarations]

Is this kept for compatibility reasons or would it be ok to submit a pullrequest with the snprintf variant?

[ernestguillem]

I see the pull request for issue #57 will fix that once it's merged.