[clean] clean code

models/training_training.py

@@ -126,9 +126,6 @@ class Training(models.Model):
     @api.multi
     def write(self, vals):
         record = super(Training, self).write(vals)
-        print(self)
-        print(record)
-        print(vals)
         if vals.get('course_id', False):
             self.session_ids.unlink()
             for s in self.course_id.session_ids: