Cannot generate docs from local

it looks like the updates over the past week have broken the ability for ember-jsonapi-docs to generate local api documentation. Not sure what is going on? Nothing appears for the new version in tmp/json-docs/ember or tmp/json-docs/ember-data

As a result, the generated version does not appear in the dropdown in ember-api-docs when running `yarn start:local`.

See also #70

Going back to commit 8a34672cffdd73fd2c1fa40139242f3af993b32a fixes that ability, although it hangs on downloading past versions.

This issue is holding up https://github.com/emberjs/data/pull/6449