[calcite-app-components] migration plan

[jcfranco]

Moving https://github.com/Esri/calcite-components/issues/801 since items are actionable here.

The following should be done once https://github.com/Esri/calcite-components/issues/689 is taken care of.

• [ ]~ xfer wikis~ will move over as needed
• [x] xfer issues
• [x] Add deprecation notices
  • [x] README.md - (add unmaintained badge? http://unmaintained.tech/)
  • [x] NPM (https://docs.npmjs.com/cli/deprecate)
• [x] Add migration wiki - https://github.com/Esri/calcite-app-components/wiki/Migration-Guide
• [x] Stop Travis builds (including auto-@next publishing)

cc @driskull @asangma @kat10140

[jcfranco]

Closing as self-verified.