0.4.0

• Documented the layout algorithm used in tubes plots.
• Added scale_bar option to demesdraw.tubes(), and --scale-bar option
  to the demesdraw tubes CLI, to draw a scale bar that indicates the
  population size.
• Removed dependency on cvxpy by going back to scipy
  for optimisation of the deme positions. The trust-constr
  method with linear constraints seems to work well.

0.3.1

• Added mouseover annotation popups for interactive tubes plots.
• Dropped support for Python 3.6.
• Performance improvement when calculating tube positions.
• Fix incompatibility with "legend" labels and matplotlib 3.6.0.

0.3.0

New features

• Improved the default positions of demes in demesdraw.tubes()
  for tree-like models and more elaborate models with many demes.
  The previously used optimisation procedure (scipy's SLSQP) has been
  removed in favour of constrained convex optimisation using cvxpy.
• Increased the default amount of space that separates demes in
  demesdraw.tubes(), and use more space when there are more
  contemporary demes (see demesdraw.util.separation_heuristic()).
• Filter numpy warnings about overflow when using a log scale.
  The overflow in question is harmless and these warnings only serve
  to confuse users.

Breaking change

• Removed the optimisation_rounds parameter to demesdraw.tubes().