Chore/dependency updates (#549)

* Updated all non-breaking dependencies

* Updated common/crypto dependencies

* Updated all tokio [and associated] dependencies to most recent version

* Bumped version of rand_distr

* Fixed api changes in tests

* Made clippy happier about the acronym

* Fixed the type while trying to make clippy even happier

* nightly cargo fmt

mixnode/src/node/mod.rs

@@ -123,7 +123,7 @@ impl MixNode {
     pub fn run(&mut self) {
         info!("Starting nym mixnode");
 
-        let mut runtime = Runtime::new().unwrap();
+        let runtime = Runtime::new().unwrap();
 
         runtime.block_on(async {
             if let Some(duplicate_node_key) = self.check_if_same_ip_node_exists().await {