Merge pull request #108 from maxsch3/feature/107

#107 changed to tensorflow==1.15.4 in requirements_TF1

Author: maxsch3

requirements_tf1.txt

@@ -5,4 +5,4 @@ pytest==5.2.1
 pytest-dependency==0.5.1
 scikit-learn==0.21.3
 scipy==1.3.1
-tensorflow==2.2.1
+tensorflow==1.15.4