Release v2.1

[gdicker1]

Incorporate changes to externals for the v2.1 release.

[gdicker1]

Relevant PRs in Externals:

• https://github.com/EarthWorksOrg/mpas-seaice/pull/6
• https://github.com/EarthWorksOrg/mpas-ocean/pull/6
• https://github.com/EarthWorksOrg/mpas-framework/pull/5
• https://github.com/EarthWorksOrg/CMEPS/pull/5
• https://github.com/EarthWorksOrg/CTSM/pull/5
• https://github.com/EarthWorksOrg/ccs_config_cesm/pull/16
• https://github.com/EarthWorksOrg/cime/pull/8
• Missed making a PR for CAM
  • https://github.com/EarthWorksOrg/MPAS-Model/pull/2