validate image resize dimensions

[ericbuehl]

Issue #, if available: -

Description of changes:
Clients who request invalid image resize dimensions should get a 4xx error rather than a 5xx

Checklist

• 👋 I have added unit tests for all code changes.
• 👋 I have run the unit tests, and all unit tests have passed.
• ⚠️ This pull request might incur a breaking change.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[dougtoppin]

@ericbuehl thank you for your submission, we will add it to our backlog for evaluation and get back to you. sorry about the delay in responding.

[ericbuehl]

hello -- any updates here?

[ericbuehl]

@dougtoppin any updates here? thank you!

[simonkrol]

Hi @ericbuehl,

As an update here, we've decided to implement this change. It would be considered a breaking change, so we've marked it to be included in the next major release. While our internal policy has us make the changes manually, once the release is out, you'll see your profile and this PR referenced in the External Contributors section towards the bottom of the readme, and this PR will be closed.

Thanks for your contributions to the Serverless Image Handler :)
Simon