public function store()
    {
        $this->validate($this->request, [
            'name'     => 'required',
            'resource' => 'required|alpha_num',
            'slug'     => 'required|unique:permissions,slug',
        ]);

        $permission = Permission::create($this->request->all());
        $permission->syncRoles($this->request->get('roles', []));

        return redirect()->route('administrator.permissions.index');
    }