update

requirements.txt

-Flask<1
+Flask>=1.0.2
+paramiko>=2.6.0
+flask-socketio>=4.1.0
+python-socketio>=4.2.0
+Werkzeug>=0.15.1
+Pillow==5.4.1
+requests>=2.20
+cffi>=1.12.3
+psutil>=5.2.0
+chardet>=3.0.4
+Flask-Session>=0.3.1
+flask-sqlalchemy>=2.3.2
+gunicorn>=18.0
+gevent-websocket>=0.10.1
+pyopenssl>=19.0
+cryptography>=2.7
+six>=1.12.0
\ No newline at end of file