Factored out common geomtry assertions in test.
Factored out more common stuff in adminizer test.
Added simple polygon tests.
Extract common pattern for adminizer tests.
Add a test for multi geometries

mapnik/mapnik#2518 prevents checking the GeoJSON, so instead the feature geometry is queried manually.

mapbox/mapnik-vector-tile#62 prevents MultiPoints from working with mapnik-vector-tile, so they don't work in Avecado either

ref mapbox/vector-tile-spec#18
Extend test coverage to all multi types

Still requires polygon with inner ring coverage
Merge pull request #21 from MapQuest/adminizer_multipolygon

Adminizer multi*