sha256 encryption

sha256：

　　1. Install using npm: npm install js-sha256

　　2. Then define the method in the methods of the component, when calling

　　

// sha256 encrypted password 
setSha(){
     let sha256 = require( " js-sha256 " ).sha256 // The require method is used here 
     this .password = sha256( this .passWord) // The password to be encrypted 
     console.log( this .password) // This is you encrypted password 
     }