update helpers.ResizeImage to return error code and do something with it here

[todo]

https://github.com/devopsdays/devopsdays-cli/blob/663f8f09d8169a858ba7881f84fbc5171d712ff9/event/event.go#L239-L243

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This issue was generated by todo based on a @todo comment in 663f8f0. It's been assigned to @mattstratton because they committed the code.