remove fxhash dep

Author: hkBst

Cargo.toml

@@ -36,7 +36,6 @@ rand = {version = "0.8", features = ["small_rng"] }
 quickcheck = { version = "1.0", default-features = false }
 fnv = "1.0"
 lazy_static = "1.3"
-fxhash = "0.2.1"
 serde_derive = "1.0"
 
 [features]