Don't run LISO tests if LISO_ACCESS_TOKEN is not found
Since LISO is not open source, the project's GitLab CI runner grabs the LISO binary from a private AEI git server using an access token (
LISO_ACCESS_TOKEN) defined in the private project settings, only accessible to me. This has the side effect that anyone forking the repository and committing changes will have the validation tests fail out.
Fix this by disabling the validation tests if the token is not found.
(props Anchal Gupta)