Refactor spec_helper requirement with rspec config

spec/views/playlists/edit.html.haml_spec.rb

@@ -1,5 +1,3 @@
-require 'spec_helper'
-
 describe 'playlists/edit' do
   let(:playlist) { mock_model(Playlist).as_new_record.as_null_object }
 

spec/views/playlists/index.html.haml_spec.rb

@@ -1,5 +1,3 @@
-require 'spec_helper'
-
 describe 'playlists/index' do
   before { assign :playlists, [mock_model(Playlist, name: 'Electro')] }
 

spec/views/playlists/new.html.haml_spec.rb

@@ -1,5 +1,3 @@
-require 'spec_helper'
-
 describe 'playlists/new' do
   let(:playlist) { mock_model(Playlist).as_new_record.as_null_object }