FIXUP for unary union commit

Author: jorisvandenbossche

geopandas/tests/test_vectorized.py

@@ -391,7 +391,7 @@ def test_unary_union():
     geoms = [shapely.geometry.Polygon([(0, 0), (0, 1), (1, 1)]),
              shapely.geometry.Polygon([(0, 0), (1, 0), (1, 1)])]
     G = from_shapely(geoms)
-    u = G.unary_union()
+    u = G.unary_union
 
     expected = shapely.geometry.Polygon([(0, 0), (1, 0), (1, 1), (0, 1)])
     assert u.equals(expected)