public function update(Request $request, Post $post) {
        $this->authorize('update', $post);

        $this->validate($request, [
            'body'  => [
                'required',
                'max:250'
            ],
        ]);

        Post::where('id', $request->route('posts'))->update([
            'content'   => $request->body
        ]);

        return back()->with('message', 'Your post has been updated.');
    }