change lastest v1 version

Author: duke-git

README.md

@@ -37,7 +37,7 @@ go get github.com/duke-git/lancet/v2 // will install latest version of v2.x.x
 
 2. <b>For users who use version below go1.18, you should install v1.x.x. now latest v1 is v1.3.1. </b>
 ```go
-go get github.com/duke-git/lancet@v1.3.0 // below go1.18, install latest version of v1.x.x
+go get github.com/duke-git/lancet@v1.3.1 // below go1.18, install latest version of v1.x.x
 ```
 
 ## Usage

README_zh-CN.md

@@ -37,7 +37,7 @@ go get github.com/duke-git/lancet/v2 //安装v2最新版本v2.x.x
 
 2. <b>使用go1.18以下版本的用户，必须安装v1.x.x。目前最新的v1版本是v1.3.1。</b>
 ```go
-go get github.com/duke-git/lancet@v1.3.0 // 使用go1.18以下版本, 必须安装v1.x.x版本
+go get github.com/duke-git/lancet@v1.3.1 // 使用go1.18以下版本, 必须安装v1.x.x版本
 ```
 
 ## 用法