Revert "Accounts with state (#954)"

This reverts commit c23fa289c3.

src/request.rs

@@ -1,13 +1,12 @@
 //! The `request` module defines the messages for the thin client.
 
-use bank::Account;
 use hash::Hash;
 use signature::{Pubkey, Signature};
 
 #[cfg_attr(feature = "cargo-clippy", allow(large_enum_variant))]
 #[derive(Serialize, Deserialize, Debug, Clone, Copy)]
 pub enum Request {
-    GetAccount { key: Pubkey },
+    GetBalance { key: Pubkey },
     GetLastId,
     GetTransactionCount,
     GetSignature { signature: Signature },
@@ -23,20 +22,9 @@ impl Request {
 
 #[derive(Serialize, Deserialize, Debug)]
 pub enum Response {
-    Account {
-        key: Pubkey,
-        account: Option<Account>,
-    },
-    LastId {
-        id: Hash,
-    },
-    TransactionCount {
-        transaction_count: u64,
-    },
-    SignatureStatus {
-        signature_status: bool,
-    },
-    Finality {
-        time: usize,
-    },
+    Balance { key: Pubkey, val: i64 },
+    LastId { id: Hash },
+    TransactionCount { transaction_count: u64 },
+    SignatureStatus { signature_status: bool },
+    Finality { time: usize },
 }