feat: init Rust VM

fix/benches/utils.rs

@@ -1,18 +1,18 @@
 #![allow(dead_code)]
 
-use fix::context::Context;
 use fix::error::{Result, Source};
+use fix::runtime::Runtime;
 use fix::value::Value;
 
 pub fn eval(expr: &str) -> Value {
-    Context::new()
+    Runtime::new()
         .unwrap()
         .eval(Source::new_eval(expr.into()).unwrap())
         .unwrap()
 }
 
 pub fn eval_result(expr: &str) -> Result<Value> {
-    Context::new()
+    Runtime::new()
         .unwrap()
         .eval(Source::new_eval(expr.into()).unwrap())
 }