Log Message:
py-test-xprocess: updated to 0.21.0

0.21.0 (2022-11-27)
-------------------

- Explicitly add `py` package as a dependency, fixing issue with `pytest` >= 7.2.0
- Process log files will not be overwritten for each new process anymore, making it
  easier to debug issues that occurred in the middle of failed test runs

0.20.0 (2022-08-29)
-------------------

- Cleanup reminders will now only be printed for verbosity
  levels equal or greater than 1

0.19.0 (2022-05-23)
-------------------

- drop support for python 3.5 and 3.6
- reorganize internals. ``pytest-xprocess`` is now a package and all resources
  used by running processes are kept as instances of :class:``XProcessResources``.

0.18.1 (2021-07-27)
-------------------

- Fix bug with previous release where internal module was missing

0.18.0 (2021-07-21)
-------------------

- :method:`ProcessInfo.terminate` will now terminate outer leaves in process
  tree first and work its way towards root process. For example, if a process
  has child and grandchild, xprocess will terminate first child and grandchild
  and only then will the root process receive a termination signal.

- :class:`ProcessStarter` now has attr:`terminate_on_interrupt`. This flag will
  make xprocess attempt to terminate and clean up all started process resources
  upon interruptions during pytest runs (`CTRL+C`, `SIGINT` and internal errors)
  when set to `True`. It will default to `False`, so if the described behaviour
  is desired the flag must be explicitly set `True`.

- Add a new `popen_kwargs` variable to `ProcessStarter`, this variable can
  be used for passing keyword values to the `subprocess.Popen` constructor,
  giving the user more control over how the process is initialized.