The implementation of a naive trie consists of three structs: "naiveTrie", "naiveTraverser" and "naiveTrieSeq".
"*naiveTrieSeq" satisfies "trie.TrieSeq" interface.
"*naiveTrie" satisfies "trie.Trie" interface, but not implement methods correctly yet.
"*naiveTrie" satisfies "trie.Trie" interface by implementing methods, but "(*naiveTrie).Traverser" is not implemented yet.
Merge branch 'feature/trie-naive-impl'