feat(api): 添加图片上传功能

为应用添加了图片上传功能，可以通过URL下载图片并进行压缩处理。

app.py

@@ -299,6 +299,17 @@ def consume():
         return jsonify(response_data), 400
 
 
+def upload_image(url):
+    # download image
+    img = requests.get(url)
+    # compress image
+    compress_url = 'https://upload-tinypng.tunpok.com/upload/'
+    resp = requests.post(compress_url, files={'file': img.content})
+    if resp.status_code == 200:
+        return resp.json()['cdn_url']
+    return None
+
+
 @app.route("/add_recipe", methods=["POST"])
 def add_recipe():
     data = request.json