Implement playlists/create action for API

spec/integration/api/playlists_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+feature 'API playlists' do
+  include UserIntegrationHelpers
+
+  background do
+    api_sign_in
+  end
+
+  scenario 'creates playlist' do
+    playlist = Factory.attributes_for :playlist
+
+    post api_playlists_path,
+      :format => :json,
+      :playlist => playlist
+
+    json = JSON response.body
+
+    json['id'].should be_a Fixnum
+    json['name'].should == playlist[:name]
+  end
+end