Update to protocol 19.34.0 (C* 1.2b1)
If the pycassa module is imported in setup.py, it will currently end up trying to import thrift. This causes issues when installing pycassa, as thrift may not yet be available.
C11 exception base class changes vs. pool retry
With the c11 thrift API update, all exceptions in ttypes inherit from TException instead of Exception. This change restores the old behavior and does not retry any of: NotFoundException, InvalidRequestException, AuthenticationException, AuthorizationException, SchemaDisagreementException Compared to pycassa 1.6.0 TProtocolException is no longer retried either.
but 19.20.0 via `version` as `c11.constants.VERSION` is the newer `19.32.0`