Fix clippy warnings (#1385)

## Issue Addressed

NA

## Proposed Changes

Fixes most clippy warnings and ignores the rest of them, see issue #1388.

account_manager/src/validator/deposit.rs

@@ -1,6 +1,5 @@
 use crate::VALIDATOR_DIR_FLAG;
 use clap::{App, Arg, ArgMatches};
-use clap_utils;
 use deposit_contract::DEPOSIT_GAS;
 use environment::Environment;
 use futures::compat::Future01CompatExt;