layers are list not numpy array

tests/test_paths.py

@@ -123,7 +123,7 @@ def test_poly(self):
 
         # layers should match entity count
         assert len(p.layers) == len(p.entities)
-        assert len(g.np.unique(p.layers)) > 1
+        assert len(set(p.layers)) > 1
 
         count = len(p.entities)