Adapt tool_policy to avoid travis errors on Github plugin project

Setup

1. Login as admin.
2. Access to "Site administration | Privacy and policies | Policy settings" and set site policy hander to “Policies (tool_policy)”.
3. Create a policy and set it as active.

Testing scenario

1. Login as admin.
2. View the policy.
   • CHECK an Edit button still appears next to Back button.
3. Clic the "Edit" button.
   • CHECK the form for editing the policy is opened.