Re-added accidentally removed test method.

Also fixed indentation.

tests/tests.rs

@@ -25,6 +25,17 @@ fn test_simple() {
     assert_eq!(sum_len, 8);
 }
 
+#[test]
+fn test_u16_index() {
+    const N: usize = 4096;
+    let mut vec: ArrayVec<[_; N]> = ArrayVec::new();
+    for _ in 0..N {
+        assert!(vec.push(1u8).is_none());
+    }
+    assert!(vec.push(0).is_some());
+    assert_eq!(vec.len(), N);
+}
+
 #[test]
 fn test_iter() {
     let mut iter = ArrayVec::from([1, 2, 3]).into_iter();