Lint: Sanity check version numbers

[michael-wisely-gravwell]

Task

What needs to be done?

Sanity check version numbers across files

• The version and url fields in an object in _static/versions.json should match (the version to the path in the URL, that is)
• Each version listed in _static/versions.json should have a change log
• Each version listed in _static/versions.json should be listed in changelog/list.md
  • Should be caught by Sphinx - otherwise we'd have a dangling file
• change log headers should match the filename
• the release version in conf.py should be present in _static/versions.json and it should be marked preferred and latest

Why is this task needed?

There are a lot of little spots to update when creating a new release. Having some automated sanity checks would help improve confidence.

Any other comments?

Marked medium to match the other Lint issue - I think having an automated check will be helpful during release. We have enough things to think about when we're publishing.