Reloading BigQuery table in system test before fetching data.

e.g. https://circleci.com/gh/GoogleCloudPlatform/google-cloud-python/2065

Error introduced in #3426.

Author: dhermes

bigquery/tests/system.py

@@ -826,6 +826,8 @@ def test_dump_table_w_public_data(self):
 
         dataset = Config.CLIENT.dataset(DATASET_NAME, project=PUBLIC)
         table = dataset.table(TABLE_NAME)
+        # Reload table to get the schema before fetching the rows.
+        table.reload()
         self._fetch_single_page(table)
 
     def test_insert_nested_nested(self):