Ability to run the OPA testsuite (#39)

`OPA_TESTS_DIR=path/to/testsuite cargo test opa -- --shot-output` to run opa tests.
Failing test cases are saved in target/opa/folder for investigation.

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

tests/parser/mod.rs

@@ -4,7 +4,6 @@
 use anyhow::{anyhow, bail, Result};
 use regorus::*;
 use serde::{Deserialize, Serialize};
-use std::env;
 use test_generator::test_resources;
 
 macro_rules! my_assert_eq {
@@ -700,24 +699,6 @@ fn yaml_test(file: &str) -> Result<()> {
     }
 }
 
-#[test]
-#[ignore = "intended for use by scripts/yaml-test-parse"]
-fn one_yaml() -> Result<()> {
-    let mut file = String::default();
-    for a in env::args() {
-        if a.ends_with(".yaml") {
-            file = a;
-            break;
-        }
-    }
-
-    if file.is_empty() {
-        bail!("missing yaml test file");
-    }
-
-    yaml_test(file.as_str())
-}
-
 #[test_resources("tests/parser/**/*.yaml")]
 fn run(path: &str) {
     yaml_test(path).unwrap()