Install packaging module if not found

[raman325]

Resolves #90

[craigbarratt]

Thanks for quickly looking into and addressing #90.

One question - is it possible to fix via just adding packaging to requirements in custom_components/pyscript/manifest.json?

[raman325]

yes, that may be a better approach, and I don't know why I didn't think of that

[raman325]

The only rub there will be that for certain installations of Home Assistant (I know the Docker container for example already has packaging), packaging is already installed, and I'm not clear on whether or not pinning it to a version will break something in the future

[craigbarratt]

Good point - it looks like requirements in manifest.json is always pinned, which is problematic for the reason you mention. I haven't looked at the code to see whether pinning is required, but it seems risky even if pinning wasn't required since all components I checked do pin.

It does seem like this PR is the best fix.

[craigbarratt]

Thanks!