v0.19.0a1

0.19.0a1

New features

• Ability to import tree sequences with mutations from tskit.
  A new {ref}vignette <import_mutations_from_tskit_vignette> describes the procedure.
  PR {pr}1026.

Bug fixes

• Fix bug in sweep models.
  The fix in PR {pr}1020 was incomplete.
  Tree span is now accounted for.
  PR {pr}1026.
• Fix Python-side constructors in Mutation re: integer types.
  No previous results were affected.
  PR {pr}1023.

Documentation

• Update developer docs.
  PR {pr}1021.