title: bundle exec rake test throwing error
body: <p>Hello there I am new to rail. I am following railstutorial.org by Michael Hartl. I am stuck in chapter 4, Listing 4.5:
  when i hit <code>$ bundle exec rake test</code> it showing some different result than it supposed to show as per tutorial. 
  Note :I am using Ubuntu 15.10 as a platform. </p>
  
  <p>Result when i hit <code>$ bundle exec rake test</code></p>
  
  <pre><code>  /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-reporters-1.0.5/lib/minitest/minitest_reporter_plugin.rb:8:in `block in plugin_minitest_reporter_init': undefined method `add_defaults' for #&lt;Guard::Minitest::Reporter:0x005580a1496930&gt; (NoMethodError)
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-reporters-1.0.5/lib/minitest/minitest_reporter_plugin.rb:6:in `each'
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-reporters-1.0.5/lib/minitest/minitest_reporter_plugin.rb:6:in `plugin_minitest_reporter_init'
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.8.4/lib/minitest.rb:74:in `block in init_plugins'
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.8.4/lib/minitest.rb:72:in `each'
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.8.4/lib/minitest.rb:72:in `init_plugins'
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.8.4/lib/minitest.rb:123:in `run'
    from /home/shyambhimani/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/minitest-5.8.4/lib/minitest.rb:56:in `block in autorun'
  </code></pre>
  
  <p>application.html.erb</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;title&gt;&lt;%= full_title(yield(:title)) %&gt;&lt;/title&gt;
      &lt;%= stylesheet_link_tag    'application', media: 'all',
                                                'data-turbolinks-track' =&gt; true %&gt;
      &lt;%= javascript_include_tag 'application', 'data-turbolinks-track' =&gt; true %&gt;
      &lt;%= csrf_meta_tags %&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;%= yield %&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>application_helper.rb</p>
  
  <pre><code>module ApplicationHelper
  
    # Returns the full title on a per-page basis.
    def full_title(page_title = '')
      base_title = "Ruby on Rails Tutorial Sample App"
      if page_title.empty?
        base_title
      else
        page_title + " | " + base_title
      end
    end
  end
  </code></pre>
  
  <p>static_pages_controller_test.rb</p>
  
  <pre><code>require 'test_helper'
  
  class StaticPagesControllerTest &lt; ActionController::TestCase
    test "should get home" do
      get :home
      assert_response :success
      assert_select "title", "Ruby on Rails Tutorial Sample App"
    end
  
    test "should get help" do
      get :help
      assert_response :success
      assert_select "title", "Help | Ruby on Rails Tutorial Sample App"
    end
  
    test "should get about" do
      get :about
      assert_response :success
      assert_select "title", "About | Ruby on Rails Tutorial Sample App"
    end
  end
  </code></pre>
  
  <p>test_helper.rb</p>
  
  <pre><code>ENV['RAILS_ENV'] ||= 'test'
  require File.expand_path('../../config/environment', __FILE__)
  require 'rails/test_help'
  require "minitest/reporters"
  Minitest::Reporters.use!
  
  class ActiveSupport::TestCase
    # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical
    # order.
    fixtures :all
  
    # Add more helper methods to be used by all tests here...
  end
  </code></pre>
  
  <p>Gemfile</p>
  
  <pre><code>source 'https://rubygems.org'
  
  gem 'rails',        '4.2.6'
  gem 'sass-rails',   '5.0.2'
  gem 'uglifier',     '2.5.3'
  gem 'coffee-rails', '4.1.0'
  gem 'jquery-rails', '4.0.3'
  gem 'turbolinks',   '2.3.0'
  gem 'jbuilder',     '2.2.3'
  gem 'sdoc',         '0.4.0', group: :doc
  
  group :development, :test do
    gem 'sqlite3',     '1.3.9'
    gem 'byebug',      '3.4.0'
    gem 'web-console', '2.0.0.beta3'
    gem 'spring',      '1.1.3'
  end
  
  group :test do
    gem 'minitest-reporters', '1.0.5'
    gem 'mini_backtrace',     '0.1.3'
    gem 'guard-minitest',     '2.3.1'
  end
  
  group :production do
    gem 'pg',             '0.17.1'
    gem 'rails_12factor', '0.0.2'
  end
  </code></pre>
  
  <p>Please guide me how can i get rid of the error. </p>