Added tests for VecTile MultiResponse
Added tests for VecTile MultiResponse

Billups/TileStache,MetGIS/TileStache,moskvax/TileStache,SEL-Columbia/TileStache,mapzen/TileStache,Billups/TileStache,jbants/TileStache,Blechhirn/TileStache,mapzen/TileStache,SEL-Columbia/TileStache,Kosta-Github/TileStache,jbants/TileStache,Blechhirn/TileStache,TileStache/TileStache,Billups/TileStache,TileStache/TileStache,MetGIS/TileStache,Blechhirn/TileStache,jbants/TileStache,TileStache/TileStache,Kosta-Github/TileStache,mapzen/TileStache,moskvax/TileStache,MetGIS/TileStache,moskvax/TileStache,Kosta-Github/TileStache,SEL-Columbia/TileStache