Exception correction

api/examples/get_example.py

@@ -28,10 +28,10 @@ def get_example(example_id):
         })
 
         example.validate()
-    except ModelConversionError, mce:
+    except ModelConversionError as mce:
         # ModelConversionError catches incorrect types
         app.logger.exception(mce.messages)
-    except ModelValidationError, mve:
+    except ModelValidationError as mve:
         # ModelValidationError catches validation errors
         app.logger.exception(mve.messages)