Updated readme. Added bundle support. (#61)

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

tests/opa.rs

@@ -57,7 +57,7 @@ fn eval_test_case(case: &TestCase) -> Result<Value> {
         values.push(if !qr.bindings.is_empty_object() {
             qr.bindings.clone()
         } else if let Some(v) = qr.expressions.last() {
-            v["value"].clone()
+            v.value.clone()
         } else {
             Value::Undefined
         });