feat: add basic support for org env vars

[rocketeerbkw]

General Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for inclusion in changelog

• Added --organization-name to add/update variable
  • Changes are backwards compatible with older lagoon API
• Added list organization-variables

Blocked on uselagoon/machinery#80.

[shreddedbacon]

You can use go get github.com/uselagoon/machinery@basic-org-env-vars to add the machinery branch and push that so that this branch can be checked out and used locally. Just revert once the code is merged and released in machinery.