Disable Rails/OutputSafety for specs

This cop is to protect against user input. There's no user input (or users) in specs.

.rubocop_styleguide.yml

@@ -70,6 +70,10 @@ Rails/SkipsModelValidations:
     - "update_column"
     - "update_columns"
 
+Rails/OutputSafety:
+  Exclude:
+    - 'spec/**/*'
+
 Style/Documentation:
   Enabled: false