Fix the conflict with iterator_tools.

Author: eranfu

Cargo.toml

@@ -27,6 +27,7 @@ permutation = "0.4.0"
 bencher = "0.1"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
+itertools = "0.14.0"
 
 [build-dependencies]
 rustc_version = "0.4"