findMinMax was returning a confusing value for empty raster
Added ZonalPercentage operation.
Performance improvements to ToVector and RegionGroup
Merge pull request #550 from lossyrob/quickfix/findMinMax

findMinMax was returning a confusing value for empty raster
Added ZonalClassification operation
Merge pull request #551 from lossyrob/mapalgebra/zonal

Added ZonalPercentage and ZonalClassification operations.
Merge pull request #552 from lossyrob/optimize/ToVector

Performance improvements to ToVector and RegionGroup
Split gtfs edge data by transit type
Merge pull request #553 from lossyrob/network/gtfs_split

Split gtfs edge data by transit type
Additional test coverge to geotrellis.logic
Merge pull request #554 from lossyrob/testcoverage

Additional test coverge to geotrellis.logic