⬆️ Bump psutil from 5.3.1 to 5.6.6

Bumps [psutil](https://github.com/giampaolo/psutil) from 5.3.1 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-5.3.1...release-5.6.6)

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

Author: dependabot[bot]

requirements.txt

@@ -12,7 +12,7 @@ Jinja2==2.9.6
 MarkupSafe==1.0
 packaging==16.8
 pbr==3.1.1
-psutil==5.3.1
+psutil==5.6.6
 pyparsing==2.2.0
 python-utils==2.2.0
 six==1.11.0