Fix clippy, update old dependencies

coordinator/tributary/src/lib.rs

@@ -253,7 +253,7 @@ impl<TD: Db, TDT: DbTxn, P: P2p> ScanBlock<'_, TD, TDT, P> {
         let signer = signer(signed);
 
         // Check the participant voted to be removed actually exists
-        if !self.validators.iter().any(|validator| *validator == participant) {
+        if !self.validators.contains(&participant) {
           TributaryDb::fatal_slash(
             self.tributary_txn,
             self.set.set,

coordinator/tributary/src/transaction.rs

@@ -5,11 +5,11 @@ use zeroize::Zeroizing;
 use rand_core::{RngCore, CryptoRng};
 
 use blake2::{digest::typenum::U32, Digest, Blake2b};
-use dalek_ff_group::Ristretto;
 use ciphersuite::{
-  group::{Group, GroupEncoding},
+  group::{ff::Field, Group, GroupEncoding},
   Ciphersuite,
 };
+use dalek_ff_group::Ristretto;
 use schnorr::SchnorrSignature;
 
 use scale::Encode;