Fixed abstract class method decoration for python 2

force_bdss/data_sources/base_data_source_model.py

@@ -3,6 +3,7 @@ import six
 
 
 class BaseDataSourceModel(six.with_metaclass(abc.ABCMeta)):
-    @abc.abstractclassmethod
+    @classmethod
+    @abc.abstractmethod
     def from_json(self, model_data):
         pass

force_bdss/kpi/base_kpi_calculator_model.py

@@ -3,6 +3,7 @@ import abc
 
 
 class BaseKPICalculatorModel(six.with_metaclass(abc.ABCMeta)):
-    @abc.abstractclassmethod
+    @classmethod
+    @abc.abstractmethod
     def from_json(self, model_data):
         pass

force_bdss/mco/base_mco_model.py

@@ -3,6 +3,7 @@ import six
 
 
 class BaseMCOModel(six.with_metaclass(abc.ABCMeta)):
-    @abc.abstractclassmethod
+    @classmethod
+    @abc.abstractmethod
     def from_json(self, model_data):
         pass