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](https://github.com/giampaolo/psutil/compare/release-5.6.3...release-5.6.6)

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

requirements.txt

@@ -16,7 +16,7 @@ scipy==1.5.4
 numpy==1.19.4
 pyproj==3.0.0
 Pysolar==0.6
-psutil==5.6.3
+psutil==5.6.6
 joblib==0.17.0
 Fiona==1.8.9.post2
 cryptography==2.8