avoid ff changes

Author: dignifiedquire

Cargo.toml

@@ -23,7 +23,8 @@ serde = { version = "1.0", optional = true, features = ["derive"] }
 fff = { version = "0.2.0", features = ["derive"] }
 groupy = "0.3.0"
 rand_core = "0.5"
-lazy_static = "1.4.0"
+hkdf = "0.8.0"
+sha2ni = "0.8.1"
 
 [dev-dependencies]
 rand_xorshift = "0.2"
@@ -36,4 +37,3 @@ default = []
 
 [badges]
 maintenance = { status = "actively-developed" }
-