Adjust `/bootlint/latest/bootlint.min.js` cache-control header

We should make `https://stackpath.bootstrapcdn.com/bootlint/latest/bootlint.min.js` not have a 1 year cache-control control header since it changes.

Do we have other files like that?

Also, note that currently it points to the old version (0.15.1).

EDIT: We should also add tests for this file.