Update Fences to 8.x-2.0-rc1

composer.json

@@ -56,7 +56,7 @@
         "drupal/externalauth": "1.2",
         "drupal/eu_cookie_compliance": "1.9",
         "drupal/features": "3.11",
-        "drupal/fences": "2.0-alpha2",
+        "drupal/fences": "2.0-rc1",
         "drupal/field_group": "3.0",
         "drupal/field_validation": "1.0-alpha7",
         "drupal/file_mdm": "2.1",