Transition new blocks from the mempool onto the blockchain.

Chime on new blocks.
fixes #47
fixes #84

backend/src/api/mempool.ts

@@ -1,6 +1,6 @@
 const config = require('../../mempool-config.json');
 import bitcoinApi from './bitcoin/electrs-api';
-import { MempoolInfo, TransactionExtended, Transaction } from '../interfaces';
+import { MempoolInfo, TransactionExtended, Transaction, VbytesPerSecond } from '../interfaces';
 
 class Mempool {
   private inSync: boolean = false;
@@ -12,7 +12,7 @@ class Mempool {
   private txPerSecondArray: number[] = [];
   private txPerSecond: number = 0;
 
-  private vBytesPerSecondArray: any[] = [];
+  private vBytesPerSecondArray: VbytesPerSecond[] = [];
   private vBytesPerSecond: number = 0;
 
   constructor() {

backend/src/interfaces.ts

@@ -222,3 +222,8 @@ export interface WebsocketResponse {
   'track-address': string;
   'watch-mempool': boolean;
 }
+
+export interface VbytesPerSecond {
+  unixTime: number;
+  vSize: number;
+}