Fixing missing assertTrue and reversion to not checking subset on append (both from rebase)

Author: mr-mcox

pandas_gbq/gbq.py

@@ -894,7 +894,7 @@ def to_gbq(dataframe, destination_table, project_id, chunksize=10000,
             connector.delete_and_recreate_table(
                 dataset_id, table_id, table_schema)
         elif if_exists == 'append':
-            if not connector.verify_schema(dataset_id, table_id, table_schema):
+            if not connector.schema_is_subset(dataset_id, table_id, table_schema):
                 raise InvalidSchema("Please verify that the structure and "
                                     "data types in the DataFrame match the "
                                     "schema of the destination table.")

pandas_gbq/tests/test_gbq.py

@@ -1279,9 +1279,8 @@ def test_verify_schema_ignores_field_mode(self):
                                      'type': 'TIMESTAMP'}]}
 
         self.table.create(TABLE_ID + test_id, test_schema_1)
-        self.assertTrue(self.sut.verify_schema(
-            self.dataset_prefix + "1", TABLE_ID + test_id, test_schema_2),
-            'Expected schema to match')
+        assert self.sut.verify_schema(
+            self.dataset_prefix + "1", TABLE_ID + test_id, test_schema_2)
 
     def test_retrieve_schema(self):
         # For pull request #24