The `--var-values` option of `regal test` not working

[anderseknert]

Not sure if something changed there that we don't properly mirror from OPA, but I'm not getting any useful info from that flag:

> go run main.go test bundle                           
bundle/regal/lsp/hover/hover_test.rego:5:
data.regal.lsp.hover_test.test_builtin_url_override: FAIL (3.611125ms)
--------------------------------------------------------------------------------
PASS: 986/987
FAIL: 1/987

vs

> go run main.go test --var-values bundle
FAILURES
--------------------------------------------------------------------------------
data.regal.lsp.hover_test.test_builtin_url_override: FAIL (5.748917ms)


SUMMARY
--------------------------------------------------------------------------------
bundle/regal/lsp/hover/hover_test.rego:5:
data.regal.lsp.hover_test.test_builtin_url_override: FAIL (5.748917ms)
--------------------------------------------------------------------------------
PASS: 986/987
FAIL: 1/987