Refactor tests and add union and difference tests
Refactor tests and add union and difference tests

geopandas/geopandas,perrygeo/geopandas,fonnesbeck/geopandas,geopandas/geopandas,jorisvandenbossche/geopandas,snario/geopandas,kwinkunks/geopandas,urschrei/geopandas,jorisvandenbossche/geopandas,geopandas/geopandas,jwass/geopandas,jdmcbr/geopandas,micahcochran/geopandas,jorisvandenbossche/geopandas,jwass/geopandas,koldunovn/geopandas,scw/geopandas,IamJeffG/geopandas,jdmcbr/geopandas,maxalbert/geopandas,ozak/geopandas,ozak/geopandas,micahcochran/geopandas