Bump tensorflow in /components/kubeflow/dnntrainer/src (#2923)

Bumps [tensorflow](https://github.com/tensorflow/tensorflow) from 1.15.0 to 1.15.2.
- [Release notes](https://github.com/tensorflow/tensorflow/releases)
- [Changelog](https://github.com/tensorflow/tensorflow/blob/master/RELEASE.md)
- [Commits](tensorflow/tensorflow@v1.15.0...v1.15.2)

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

components/kubeflow/dnntrainer/src/setup.py

@@ -28,7 +28,7 @@
   long_description="""
   """,
   install_requires=[
-    'tensorflow==1.15.0',
+    'tensorflow==1.15.2',
   ],
   package_data={
   },