Log Message:
Update databases/py-cassandra-driver to 3.11.0.

Features
--------
- Add idle_heartbeat_timeout cluster option to tune how long to wait
  for heartbeat responses.
- Add HostFilterPolicy

Bug Fixes
---------
- is_idempotent flag is not propagated from PreparedStatement to
  BoundStatement
- Fix asyncore hang on exit
- Driver takes several minutes to remove a bad host from session
- Installation doesn't always fall back to no cython in Windows
- Avoid to replace a connection that is supposed to shutdown
- request_ids may not be returned to the pool
- Fix murmur3 on big-endian systems
- Ensure unused connections are closed if a Session is deleted by the
  GC
- Fix .values_list by using db names internally (cqlengine)

Other
-----
- Bump Cython dependency version to 0.25.2
- Fix DeprecationWarning when using lz4
- Deprecate WhiteListRoundRobinPolicy
- Improve upgrade guide for materializing pages
- Documentation for time/date specifies timestamp inupt as
  microseconds
- Point to DSA Slack, not IRC, in docs index