Fixed problem with Beta Calibration

- Added Beta calibration as a requirement

Author: perellonieto

Diff for: pycalib/models/calibrators.py

@@ -19,10 +19,7 @@
 from sklearn.svm import LinearSVC
 from sklearn.model_selection import check_cv
 
-
-# TODO Remove BetaCalibration
-class BetaCalibration(object):
-    pass
+from betacal import BetaCalibration
 
 
 class _DummyCalibration(BaseEstimator, RegressorMixin):

Diff for: requirements.txt

@@ -4,3 +4,4 @@ scikit-learn>=0.24
 matplotlib>=3.3
 statsmodels>=0.12
 orange3>=3.28
+betacal>=1.1.0