Remove Python 3.5 compatibility on master branch

mautrix_appservice/appservice.py

mautrix_appservice/errors.py

mautrix_appservice/intent_api.py

mautrix_appservice/state_store.py

mautrix_telegram/__main__.py

mautrix_telegram/commands.py

mautrix_telegram/config.py

mautrix_telegram/db.py

mautrix_telegram/formatter.py

mautrix_telegram/matrix.py

mautrix_telegram/portal.py

mautrix_telegram/puppet.py

mautrix_telegram/tgclient.py

mautrix_telegram/user.py

requirements.txt

setup.py