title: Getting boolean instead of record when authorizing with Pundit
body: <p>According to <a href="https://github.com/elabs/pundit#policies" rel="nofollow noreferrer">the Pundit readme</a> <code>authorize</code> should return the record, yet when I'm calling it I'm getting <code>true</code>.</p>
  
  <blockquote>
    <p>authorize returns the object passed to it, so you can chain it like
    this:</p>
    
    <p>Controller:</p>
  
  <pre><code>def show
    @user = authorize User.find(params[:id])
  end
  </code></pre>
  </blockquote>
  
  <p>Gemfile:</p>
  
  <pre><code>gem 'rails', '~&gt; 5.1.1'
  gem 'devise', '~&gt; 4.3'
  gem 'pundit', '~&gt; 1.1'
  </code></pre>
  
  <p>My controller:</p>
  
  <pre><code>class PostsController &lt; ApplicationController
    skip_before_action :authenticate_user!, only: [:show, :index]
    before_action :set_post, only: [:show, :edit, :update, :destroy]
  
    def show
      # just for debugging purposes
      raise "Post is a #{@post.class.name}!" unless @post.is_a? Post
    end
  
    def set_post
      # this should return an instance of post
      @post = authorize Post.find(params[:id])
    end
  end
  </code></pre>
  
  <p>Policy:</p>
  
  <pre><code>class PostPolicy &lt; ApplicationPolicy
  
    class Scope &lt; Scope
      def resolve
        scope.all
      end
    end
  
    def show?
      true
    end
  
    # ...
  end
  </code></pre>
  
  <p>Spec:</p>
  
  <pre><code>require 'rails_helper'
  RSpec.describe "Posts", type: :request do
    subject { response }
  
    describe "GET /posts/:id" do
      let!(:post) { create(:post) }
      before { get post_path(post) }
      it { should be_successful }
    end
  end
  </code></pre>
  
  <p>Failure message: </p>
  
  <pre><code>  4) Posts GET /posts/:id 
       Failure/Error: raise "Post is a #{@post.class.name}!" unless @post.is_a? Post
  
       RuntimeError:
         Post is a TrueClass!
  </code></pre>
  
  <p>While its pretty simple to remedy this by:</p>
  
  <pre><code>def set_post
    @post = Post.find(params[:id]).tap do |p|
      @post = Post.find(params[:id]).tap { |r| authorize r }
    end
  end
  </code></pre>
  
  <p>Im very curious as to why its not working as stated by the readme. Is this a bug or am I just missing something?</p>