Fix tests.

tests/arrays.rs

@@ -13,6 +13,7 @@ fn test_arrays() -> Result<(), Box<EvalAltResult>> {
     );
     assert!(engine.eval::<bool>("let y = [1, 2, 3]; 2 in y")?);
 
+    #[cfg(not(feature = "no_object"))]
     assert_eq!(
         engine.eval::<INT>(
             r"
@@ -35,7 +36,7 @@ fn test_arrays() -> Result<(), Box<EvalAltResult>> {
             r"
                 let x = [1, 2, 3];
                 x += [4, 5];
-                x.len()
+                len(x)
            "
         )?,
         5

tests/for.rs

@@ -31,6 +31,7 @@ fn test_for_array() -> Result<(), Box<EvalAltResult>> {
 }
 
 #[cfg(not(feature = "no_object"))]
+#[cfg(not(feature = "no_index"))]
 #[test]
 fn test_for_object() -> Result<(), Box<EvalAltResult>> {
     let engine = Engine::new();