Terraform Release for R13 v0.7.0

[morlandi7]

Release checklist

• Make sure all examples and docs reference the new provider version. Update docs to new version 0.7.0 #395
• Make sure the VERSION and internal/provider/version.go files have the new version you want to release.
• Make sure the oxide SDK dependency is up to date with the latest release. Update SDK to v0.3.0 #399
• Generate changelog by running make changelog and add date of the release to the title. Changelog for 0.7.0 #400
• Release the new version draft by running make tag.
• Verify the release is correct, it's being created from the correct tag on GitHub, and make the release live. Note: Terraform registry will silently fail to publish if the tag is incorrect, and GitHub has a habit of messing up the tag a release is created from on occasion.
• Verify the release is available on the Terraform provider registry.
• If this is not a minor patch, create a new branch with the current version
• Update to upcoming version in VERSION, internal/provider/version.go, and
  create new changelog tracker file in .changelog/ for the relevant branches. Version bump to 0.8.0 #401

[karencfv]

Tested on colo rack, all tests passed. (Just a few errors with insufficient external IP addresses but that's expected)

[karencfv]

Also tested on dogfood, tests are happy