Reformat imports to a consistent style for imports

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

banks-interface/src/lib.rs

@@ -1,13 +1,15 @@
-use serde::{Deserialize, Serialize};
-use solana_sdk::{
-    account::Account,
-    clock::Slot,
-    commitment_config::CommitmentLevel,
-    fee_calculator::FeeCalculator,
-    hash::Hash,
-    pubkey::Pubkey,
-    signature::Signature,
-    transaction::{self, Transaction, TransactionError},
+use {
+    serde::{Deserialize, Serialize},
+    solana_sdk::{
+        account::Account,
+        clock::Slot,
+        commitment_config::CommitmentLevel,
+        fee_calculator::FeeCalculator,
+        hash::Hash,
+        pubkey::Pubkey,
+        signature::Signature,
+        transaction::{self, Transaction, TransactionError},
+    },
 };
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
@@ -47,8 +49,10 @@ pub trait Banks {
 
 #[cfg(test)]
 mod tests {
-    use super::*;
-    use tarpc::{client, transport};
+    use {
+        super::*,
+        tarpc::{client, transport},
+    };
 
     #[test]
     fn test_banks_client_new() {