Pin rspec to 2.x.

Gemfile

@@ -2,6 +2,7 @@ source ENV['GEM_SOURCE'] || "https://rubygems.org"
 
 group :development, :test do
   gem 'rake',                   :require => false
+  gem 'rspec', '~> 2.11',       :require => false
   gem 'rspec-puppet',           :require => false
   gem 'puppetlabs_spec_helper', :require => false
   gem 'simplecov',              :require => false