Set iceTransportPolicy: 'relay' on the top page and the object detection app

Fix all the demos to use Twilio STUN/TURN servers

Fix path

Update streamlit==1.19.0 and object detection demo

Update app.py

Fix to use session_state as a session_specific cache

Upgrade streamlit-webrtc to 0.40.0 and update app.py to use class-less callbacks

Update app.py

Update app.py adding buy-me-a-coffee badge

Update app.py

Update app.py

Update app.py

Update app.py

Fix

Set audio_receiver_size=256

Update app.py and requirements.txt

Update app.py

Update app.py

Fix app.py

Update app.py

Update streamlit-webrtc to 0.7.0

Update app.py

Update streamlit-webrtc to 0.6.0

Update to be compatible with python 3.6 and 3.7

Update to 0.3.0

Update app.py and add heroku files