[docs] fix minor typo

[missinglink]

fix minor typo

[missinglink]

the units tests seem to be failing for an unrelated issue.

[albarrentine]

Hm, the builds have been spotty since moving the models from Mapzen's S3 buckets to Github. Suspect it has something to do with using the Github API rather than curl to get the last updated timestamps. It's unauthenticated so that might be a no-no on shared Travis instances which may also be using the API in ways that are outside of our control.

Now that everything's on Github we might want to make every model update (dictionary changes, etc. which build automatically on Travis) push a new release and then use an in-repo file to track which version of the model is currently being used.