consider adding geom=false to show/tiger endpoint

[tbuckl]

a user might just want the properties of a set of geoid's, not the whole geojson representation. one can pass a geom=false to this tiger api call but that doesn't have the convenience of getting various summary levels for some certain geoid.

here's an example use case:
https://github.com/tombuckley/census-pandas/commit/7034982152af51737f19d2e934c5d45d7d5b3dbf#diff-e1eada26a892b59872fe0612cf14b204R57

[iandees]

Yep, that makes sense.