Enhancements to docker image used for RAT runs
The changes are
- Include
libffi-dev
in the image (Related to omnibus-gitlab#6467 (closed)) - Rename image name from
gitlab_provisioner
torat
- Bump ansible version to 4.7.0, the latest
- Bump terraform version to 1.0.9, the latest (and recommended for GET)
- Includes changing the public key used for GPG validation.