Bump psutil from 5.4.3 to 5.6.6

Bumps [psutil](https://github.com/giampaolo/psutil) from 5.4.3 to 5.6.6.
- [Release notes](https://github.com/giampaolo/psutil/releases)
- [Changelog](https://github.com/giampaolo/psutil/blob/master/HISTORY.rst)
- [Commits](giampaolo/psutil@release-5.4.3...release-5.6.6)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -21,7 +21,7 @@ MarkupSafe==1.0
 mccabe==0.6.1
 mypy==0.560
 notify_run_server>=0.0.6
-psutil==5.4.3
+psutil==5.6.6
 py-vapid>=1.7.0
 pycodestyle==2.3.1
 pycparser==2.18