docs(readme): append size

docs: remove unused

Author: WittBulter

README.md

@@ -4,7 +4,7 @@
 </div>
 
 <br><br><br>
-### back-loader
+### back-loader (~ 1.2kb gzipped)
 > a easy and steady preload lib, you can use it to load all kinds of resources. 
 
 >use **back-loader** in your project, you can quickly preload more pictures, styles(.css) or scripts, it will make your website more fluent.

test/core/event.ts

@@ -1,5 +1,5 @@
 import { EventHub } from '../../src/core/event'
-import { expect, assert } from 'chai'
+import { expect } from 'chai'
 import { install } from '../dom.nyc'
 
 describe('Core function test', () => {