Conform to OPA 0.61.0. (#118)

Implement `import rego.v1`
https://www.openpolicyagent.org/docs/latest/policy-language/#the-regov1-import

- `if` required before rule body
- import rego.v1 automatically imports future.keywords
- handle import shadowing
- data, input cannot be shadowed
- deprecated functions as disallowed
- rules must have assignment or body
- `contains` required for parital set

Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>

src/tests/interpreter/mod.rs

@@ -84,7 +84,6 @@ fn match_values(computed: &Value, expected: &Value) -> Result<()> {
 
 pub fn check_output(computed_results: &[Value], expected_results: &[Value]) -> Result<()> {
     if computed_results.len() != expected_results.len() {
-        dbg!((&computed_results, &expected_results));
         bail!(
             "the number of computed results ({}) and expected results ({}) is not equal",
             computed_results.len(),