Bump tensorflow from 2.2.0 to 2.2.1

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 2.2.0 to 2.2.1.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v2.2.0...v2.2.1)

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

Author: dependabot[bot]

requirements.txt

@@ -8,5 +8,5 @@ pyyaml==5.3.1
 scikit-learn==0.22.2.post1
 scipy==1.4.1
 seaborn==0.9.1
-tensorflow==2.2.0
+tensorflow==2.2.1
 tensorflow-estimator==2.2.0