adding validate() in estimator

src/rail/core/data.py

@@ -244,7 +244,7 @@ def make_name(cls, tag):
 
     @classmethod
     def _check_data_columns(cls, path, columns_to_check, parent_groupname=None, **kwargs):
-        raise NotImplementedError
+        raise NotImplementedError # pragma: no cover
 
 
 class TableHandle(DataHandle):

src/rail/estimation/estimator.py

@@ -100,6 +100,7 @@ def estimate(self, input_data):
             Handle providing access to QP ensemble with output data
         """
         self.set_data("input", input_data)
+        self.validate()
         self.run()
         self.finalize()
         return self.get_handle("output")