确认添加朋友
<blockquote>
<p>[POST] /addFriend</p>
</blockquote>
<h3>request</h3>
<pre><code>{
"userID": int,
"friendID": int,
}</code></pre>
<h3>response</h3>
<pre><code>{
"success": bool,
"data": "",
"code": [状态码],
"msg": String
}</code></pre>