Log Message:
Update to latest relese, 1.4.2. Use DIST_SUBDIR, since this is a github
distfile. From Changelog:

1.4.2
=====

- Heartbeat negotiation would use heartbeat value from server even
  if heartbeat disabled (Issue #31).

1.4.1
=====

- Fixed error occurring when heartbeats disabled.

1.4.0
=====

- Heartbeat implementation improved (Issue #6).

    The new heartbeat behavior is the same approach as taken by the
    RabbitMQ java library.

    This also means that clients should preferably call the ``heartbeat_tick``
    method more frequently (like every second) instead of using the old
    ``rate`` argument (which is now ignored).

    - Heartbeat interval is negotiated with the server.
    - Some delay is allowed if the heartbeat is late.
    - Monotonic time is used to keep track of the heartbeat
      instead of relying on the caller to call the checking function
      at the right time.
- NoneType is now supported in tables and arrays.
- SSLTransport: Now handles ``ENOENT``.