fix: Fixing broken dependency in tsfresh

tsfresh depends on statsmodel, but doesn't specify a version. It uses a
functionality that is deprecated in version 0.13.0 and this causes the
tests to fail. Fixing the issue by adding a dependency on statsmodel==0.12.2.
This can be modified when tsfresh update their code to the new statsmodel API.

Author: Zohar Karnin

requirements.txt

@@ -4,3 +4,4 @@ scikit-learn==0.23.2
 python-dateutil==2.8.0
 pandas==1.2.4
 tsfresh==0.18.0
+statsmodels==0.12.2