Merge ~jslarraz/review-tools:unify-schema-validation into review-tools:master

[Jorge Sancho Larraz]

rt/tests/s/test_schema_base.py: fix error handling

diff --git a/reviewtools/tests/schemas/test_schema_base.py b/reviewtools/tests/schemas/test_schema_base.py
index d6c4536..cf29758 100644
--- a/reviewtools/tests/schemas/test_schema_base.py
+++ b/reviewtools/tests/schemas/test_schema_base.py
@@ -1,4 +1,3 @@
-import json
 import copy
 import unittest
 from reviewtools.schemas.schema_validator import validate
@@ -27,6 +26,7 @@ class TestSchemaBase(unittest.TestCase):
 
         # Compare the errors against the expected ones
         if expected_error is None:
-            self.assertIsNone(e.message)
+            self.assertIsNone(e)
         else:
+            self.assertIsNotNone(e)
             self.assertIn(expected_error, e.message)