Fixed bug reporting non-existing path.

train_model.py

@@ -289,7 +289,7 @@ def load_training_data(jmh_results_filename,
             # OK.
             continue
         else:
-            raise "The path '{0}' does not exist".format(file)
+            raise Exception("The path '{0}' does not exist".format(file))
 
     # Ok here we go
     jmh_with_best = load_jmh_data(jmh_results_filename)