mapbox API key required?

[tomwayson]

When I clone and run master locally I don't see the maps and I see 3 mapbox API requests that fail with Failed to load resource: the server responded with a status of 401 (Unauthorized):

I don't see anything in the instructions about how to configure an API key, though I do see this:

super-rentals/app.json

Lines 12 to 14 in 288834b

	"GOOGLE_MAPS_API_KEY": {
	"description": "Google API KEY for Google Maps, https://developers.google.com/maps/documentation/javascript/get-api-key",
	"required": true

Which seems possibly outdated?

I see the same errors with what is currently deployed at https://ember-learn-super-rentals.herokuapp.com/rentals