Release 1.0.1

Changes:

• Add logging of error message when asynchronous task fails in AsyncExecutor.
  (#265)
• Fix connection problems with fetching token ranges from hosts with
  rpc_address different than listen_address.
  Log host address(es) and ports on connection failures.
  Close thrift transport if connection fails for some reason after opening the transport,
  e.g. authentication failure.
• Upgrade cassandra driver to 2.0.6.