Reformat imports to a consistent style for imports

rustfmt.toml configuration:
  imports_granularity = "One"
  group_imports = "One"

runtime/tests/stake.rs

@@ -1,28 +1,30 @@
 #![allow(clippy::integer_arithmetic)]
-use solana_runtime::{
-    bank::Bank,
-    bank_client::BankClient,
-    genesis_utils::{create_genesis_config_with_leader, GenesisConfigInfo},
-};
-use solana_sdk::{
-    account::from_account,
-    account_utils::StateMut,
-    client::SyncClient,
-    message::Message,
-    pubkey::Pubkey,
-    signature::{Keypair, Signer},
-    stake::{
-        self, instruction as stake_instruction,
-        state::{Authorized, Lockup, StakeState},
+use {
+    solana_runtime::{
+        bank::Bank,
+        bank_client::BankClient,
+        genesis_utils::{create_genesis_config_with_leader, GenesisConfigInfo},
     },
-    sysvar::{self, stake_history::StakeHistory},
+    solana_sdk::{
+        account::from_account,
+        account_utils::StateMut,
+        client::SyncClient,
+        message::Message,
+        pubkey::Pubkey,
+        signature::{Keypair, Signer},
+        stake::{
+            self, instruction as stake_instruction,
+            state::{Authorized, Lockup, StakeState},
+        },
+        sysvar::{self, stake_history::StakeHistory},
+    },
+    solana_stake_program::stake_state,
+    solana_vote_program::{
+        vote_instruction,
+        vote_state::{Vote, VoteInit, VoteState, VoteStateVersions},
+    },
+    std::sync::Arc,
 };
-use solana_stake_program::stake_state;
-use solana_vote_program::{
-    vote_instruction,
-    vote_state::{Vote, VoteInit, VoteState, VoteStateVersions},
-};
-use std::sync::Arc;
 
 fn next_epoch(bank: &Arc<Bank>) -> Arc<Bank> {
     bank.squash();