I believe this Rake problem has been fixed upstream.

Ashley Penney · Ashley Penney · commit 101b524ca0c4 · 2014-04-10T17:34:57.000Z
diff --git a/Gemfile b/Gemfile
@@ -2,7 +2,6 @@ source ENV['GEM_SOURCE'] || 'https://rubygems.org'
 
 group :development, :test do
   gem 'mime-types', '<2.0',      :require => false
-  gem 'rake',  '10.1.1',         :require => false
   gem 'rspec-puppet',            :require => false
   gem 'puppetlabs_spec_helper',  :require => false
   gem 'serverspec',              :require => false
diff --git a/Rakefile b/Rakefile
@@ -1,2 +1 @@
 require 'puppetlabs_spec_helper/rake_tasks'
-require 'rspec-system/rake_task'

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1 @@`
`1`	`1`	`require 'puppetlabs_spec_helper/rake_tasks'`
`2`		`-require 'rspec-system/rake_task'`