Update psutil to 5.4.1

[pyup-bot]

There's a new version of psutil available.
You are currently using 5.4.0. I have updated it to 5.4.1

These links might come in handy: PyPI | Changelog | Repo

Changelog

5.4.1

=====

2017-11-08

Enhancements

• 1164_: [AIX] add support for Process.num_ctx_switches(). (patch by Arnon
  Yaari)
• 1053_: abandon Python 3.3 support (psutil still works but it's no longer
  tested).

Bug fixes

• 1150_: [Windows] when a process is terminate()d now the exit code is set to
  SIGTERM instead of 0. (patch by Akos Kiss)
• 1151_: python -m psutil.tests fail
• 1154_: [AIX] psutil won't compile on AIX 6.1.0. (patch by Arnon Yaari)
• 1167_: [Windows] net_io_counter() packets count now include also non-unicast
  packets. (patch by Matthew Long)

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖