Clippy clean (#536)

* Change into_iter to iter

* Fix clippy 'easy' warnings

* Clippy eth2/utils

* Add struct NetworkInfo

* Clippy for types, utils, and beacon_node/store/src/iters.rs

* Cargo fmt

* Change foo to my_foo

* Remove complex signature

* suppress clippy warning for unit_value in benches

* Use enumerate instead of iterating over range

* Allow trivially_copy_pass_by_ref in serde_utils

beacon_node/rest_api/src/helpers.rs

@@ -68,11 +68,11 @@ pub fn parse_pubkey(string: &str) -> Result<PublicKey, ApiError> {
         let pubkey = PublicKey::from_bytes(pubkey_bytes.as_slice()).map_err(|e| {
             ApiError::BadRequest(format!("Unable to deserialize public key: {:?}.", e))
         })?;
-        return Ok(pubkey);
+        Ok(pubkey)
     } else {
-        return Err(ApiError::BadRequest(
+        Err(ApiError::BadRequest(
             "Public key must have a  '0x' prefix".to_string(),
-        ));
+        ))
     }
 }