Changes for 0.65.1

.. code-block:: text

removed add_axes and add_subplot from backend_bases. Use figure.add_axes and add_subplot instead. The figure now manages the current axes with gca and sca for get and set current axes. If you have code you are porting which called, e.g., figmanager.add_axes, you can now simply do figmanager.canvas.figure.add_axes.