This integration is called a tag injector so as to not suggest it's as
fully-featured as a modern tag manager. But the basic idea is there: this is an
analytics.js integration that takes in settings, and creates <script> tags on
the page with those settings.
Why does this exist? See:
https://paper.dropbox.com/doc/PRD-Tag-Injector-dNWcO50rHexDvzfbaWNKe