Upstream rottage in matplotlib - papertype unknown

[bennahugo]

Caught by Montblanc test cases

values to real discards the imaginary part
  fill_value = np.array(fill_value, copy=False, dtype=ndtype)
�[0m�[91mTraceback (most recent call last):
  File "/usr/local/bin/plot-ms.py", line 720, in <module>
    plotcoll.make_figure(keys, save=savefile, suptitle=title0, figsize=figsize,
  File "/usr/local/lib/python3.8/dist-packages/Owlcat/Plotting.py", line 205, in make_figure
    fig.savefig(save, papertype=papertype, dpi=dpi,
  File "/usr/local/lib/python3.8/dist-packages/matplotlib/figure.py", line 3272, in savefig
    self.canvas.print_figure(fname, **kwargs)
  File "/usr/local/lib/python3.8/dist-packages/matplotlib/backend_bases.py", line 2338, in print_figure
    result = print_method(
  File "/usr/local/lib/python3.8/dist-packages/matplotlib/backend_bases.py", line 2204, in <lambda>
    print_method = functools.wraps(meth)(lambda *args, **kwargs: meth(
  File "/usr/local/lib/python3.8/dist-packages/matplotlib/_api/deprecation.py", line 385, in wrapper
    arguments = signature.bind(*inner_args, **inner_kwargs).arguments
  File "/usr/lib/python3.8/inspect.py", line 3037, in bind
    return self._bind(args, kwargs)
  File "/usr/lib/python3.8/inspect.py", line 3026, in _bind
    raise TypeError(
TypeError: got an unexpected keyword argument 'papertype'