fix doctest by adding sort to column name list

wntr/gis/network.py

@@ -143,6 +143,7 @@ def _extract_geodataframe(df, crs=None, valid_base_names=None,
 
                 # Add back in valid base attributes that had all None values
                 cols = list(set(valid_base_names) - set(df.columns))
+                cols.sort()
                 if len(cols) > 0:
                     df[cols] = None