Merge pull request #2568 from matrix-org/rav/pep8

synapse/app/_base.py

synapse/appservice/scheduler.py

synapse/config/server.py

synapse/crypto/context_factory.py

synapse/crypto/event_signing.py

synapse/crypto/keyring.py

synapse/event_auth.py

synapse/events/spamcheck.py

synapse/federation/transport/server.py

synapse/handlers/federation.py

synapse/handlers/initial_sync.py

synapse/handlers/message.py

synapse/handlers/presence.py

synapse/handlers/profile.py

synapse/handlers/register.py

synapse/handlers/room.py

synapse/handlers/search.py

synapse/http/matrixfederationclient.py

synapse/http/server.py

synapse/http/servlet.py