Add functions to query census.gov's API

[ramhiser]

Currently, noncensus munges much of the data provided in raw form from census.gov. The Census Bureau recently introduced a data API that requires an API key.

Functions should be written to query the API and download the data in the appropriate format. These data can then be transformed into a standard format (e.g., CSV, TopoJSON, GeoJSON) for consumption.

[ramhiser]

There's been some movement on this front. See these slides for details.

[ramhiser]

Slides refer to the censusapi package.