~~~~~~~~~~~~~~~~~~~
* Added official support for Python 2.7, 3.3, 3.4, and 3.5.
* Added a comprehensive suite of unit tests with over 90% code coverage.
* Dependencies (click and psutil) are no longer pinned to specific versions.
* Fixed bug with ``atexit`` handlers not being called in intermediate processes.
* Fixed bug when PID file is a relative path.
* Fixed bug when STDIN doesn't have a file descriptor number.
* Fixed bug when running in non-detached mode in a Docker container.
* A TTY is no longer checked for when deciding how to run in non-detached mode.
The behavior was inconsistent across different platforms.
* Fixed bug when a process stopped before having chance to check if it stopped.
* Fixed bug where an exception could be raised if a PID file is already gone
when trying to remove it.
* Subdirectories created for PID files now respect the ``umask`` setting.
* The pre-``umask`` mode for PID files is now ``0o666`` instead of ``0o777``,
which will result in a default mode of ``0o644`` instead of ``0o755`` when
using the default ``umask`` of ``0o22``.