v0.19.0

A minor release that adds face melting to ISMIP6 processing for land ice and includes some bug fixes to land-ice scripts and sea-ice partitioning tools

Minor enhancement

• Add facemelting to ismip6 processing script #490

Bug fixes

• Do not allow (t-1) to access last time level in face-melt processing #493
• Fix flux files processing when no threshold calving cells are boundary cells #494
• Allow external mapping file for sea-ice partitioning #499

Documentation

• Update docs for sea-ice partitioning #500

Contributors:

@matthewhoffman
@trhille
@xylar