0.1:

 * Initial release

0.2:

 * Added `Lock` class to help prevent cache race conditions

0.3:

 * Now actually returning the file descriptor from the `Lock` class

0.4:

 * Fixing a few bugs, added coveralls support, switched to py.test and added 100% test coverage.

    - Fixing exception thrown when fail_when_locked is true
    - Fixing exception "Lock object has no attribute '_release_lock'" when
      fail_when_locked is true due to the call to Lock._release_lock() which fails
      because _release_lock is not defined.

0.5:

 * Python 3 support
