Bump psutil from 5.4.6 to 5.6.6

Bumps [psutil](https://github.com/giampaolo/psutil) from 5.4.6 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-5.4.6...release-5.6.6)

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

Author: dependabot[bot]

requirements.txt

@@ -23,7 +23,7 @@ sqlalchemy_utils==0.33.3
 pyspark==2.4.4
 pyspark-iforest==2.4.0
 es_retriever==1.0.0
-psutil==5.4.6
+psutil==5.6.6
 psycopg2==2.7.5
 yellowbrick==0.8
 dateparser==0.7.0

requirements_unit_tests.txt

@@ -20,7 +20,7 @@ tzwhere==3.0.3
 pytz==2014.10
 sqlalchemy_utils==0.33.3
 pyspark==2.4.4
-psutil==5.4.6
+psutil==5.6.6
 psycopg2==2.7.5
 yellowbrick==0.8
 dateparser==0.7.0