Release v1.2.0

Adjusting to account for removal of set-env and add-path GH Action commands.

More details here:

• https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/
• https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-commands-for-github-actions#environment-files