Update app.py

app.py

@@ -16,4 +16,6 @@ def static_proxy(path):
     return send_from_directory('.', path)
 
 if __name__ == '__main__':
-    app.run(host='0.0.0.0', port=7860)
+    import os
+    port = int(os.environ.get('PORT', 8000))
+    app.run(host='0.0.0.0', port=port)