Fix child iterator example.

.gitignore

@@ -2,4 +2,5 @@ target
 Cargo.lock
 *.swp
 *.swo
+.DS_Store
 .cargo

examples/child_iter.rs

@@ -1,6 +1,6 @@
 extern crate radix_trie;
 
-use radix_trie::Trie;
+use radix_trie::{Trie, TrieCommon};
 
 fn main() {
     let mut t = Trie::new();
@@ -9,16 +9,12 @@ fn main() {
     t.insert("abb", 6);
     t.insert("abc", 50);
 
-    // FIXME
     // This is a bit of a hack that relies on knowing the binary representation of
     // strings... "abd" works, but "abz" doesn't...
-    /*
-    let ab_sum = t.get_raw_ancestor(&"abd").child_iter().fold(0, |acc, c| {
+    let ab_sum = t.get_raw_ancestor(&"abd").children().fold(0, |acc, c| {
         println!("Iterating over child with value: {:?}", c.value());
         acc + *c.value().unwrap_or(&0)
     });
-    */
-    let ab_sum = 0;
     println!("{}", ab_sum);
     assert_eq!(ab_sum, 5 + 6 + 50);
 }