Updated package needed for Hello Web App deployment

I was recently alerted to the fact that one of the packages I use in Hello Web App, waitress, had been updated to a version that is backwards incompatible with the book. This package was installed by my own package (hellowebapp-deploy), where I didn't specify version numbers.

This is a quick update to let y'all know that I've updated the hellowebapp-deploy pypi package to specify the correct, non-breaking version number and that I've added this to my list of things to update in a new version of the book.

If anyone would like to reinstall to get the correct version number, use this (which’ll also prevent install from the old/cached version):

pip install hellowebapp-deploy --no-cache-dir

I should have a new release for Hello Web App soon using the newest version of the whitenoise package. Stay tuned!