Log Message:
regal: Update to 0.30.0

Changes:
Regal v0.30.0 is the first release to fully support OPA 1.0 while at
the same time being fully compatible with older versions of OPA and
Rego. This process helped improve both Regal and OPA, as a few things
to fix in both projects got identified along the way!

- Full support for OPA 1.0, while maintaining compatibility with
  earlier versions
- Much faster linting