Bump tensorflow from 1.13.2 to 1.15.2 in /hyperlpr_py3

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 1.13.2 to 1.15.2.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](https://github.com/tensorflow/tensorflow/compare/v1.13.2...v1.15.2)

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

hyperlpr_py3/requirements.txt

@@ -46,7 +46,7 @@ six==1.14.0
 sklearn==0.0
 SQLAlchemy==1.3.15
 tensorboard==1.13.1
-tensorflow==1.13.2
+tensorflow==1.15.2
 tensorflow-estimator==1.13.0
 termcolor==1.1.0
 Theano==1.0.4