use zip code data to connect to other data

[scimap]

As an exhibit developer, I would like to use zip code data to tie in to other data available by zip code (e.g. salary, health indicators, elevation). #51

[bryankennedy]

@azuldev1 we should think about this when we're working on the signup screen. We should build in the ability to add zip code at some point in the signup.

This also relates to the work to localize the geomap #76

We may need some system to geocode a zip code.