0.1.0

First stable release of demes.

Breaking changes:

• The interpretation has been changed for symmetric migrations when the
  start_time (and/or end_time) is not specified. Symmetric migrations are
  now resolved separately for each pair in the list of participating demes.
  To accommodate this semantic change, the SymmetricMigration class has
  been removed, and symmetric migrations are always resolved into pairs of
  AsymmetricMigration objects.
  (@grahamgower, #263, #268)

• The size_function field can no longer be an arbitrary string.
  Only the "constant" and "exponential" strings are recognised.
  (#262, #278)

New features:

• The from_ms() function has been added to convert an ms command line
  into a Graph.
  (@jeromekelleher, @grahamgower, #74, #102)

Bug fixes:

• Graph.in_generations() no longer changes time values for a graph
  when time_units == "generations" and generation_time is not None.
  (@grahamgower, #273, #274)