paste grid_ref and grid_str to fig in make_subplots

Author: etpinard

plotly/tools.py

@@ -1086,6 +1086,10 @@ def _pad(s, cell_len=cell_len):
         print(grid_str)
 
     fig = graph_objs.Figure(layout=layout)
+
+    fig['_grid_ref'] = grid_ref
+    fig['_grid_str'] = grid_str
+
     return fig