Bump psutil from 5.6.3 to 5.6.6

Bumps [psutil](https://github.com/giampaolo/psutil) from 5.6.3 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-5.6.3...release-5.6.6)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -65,7 +65,7 @@ Pillow==6.1.0
 pkginfo==1.4.2
 prometheus-client==0.7.1
 prompt-toolkit==2.0.9
-psutil==5.6.3
+psutil==5.6.6
 pycroscopy==0.59.8
 Pygments==2.4.2
 PyInstaller==3.5