update rspec-puppet gem version to ~> 2.1.0

For compatibility with puppet 4.0.0

Author: Joshua Hoblitt

Gemfile

@@ -19,7 +19,7 @@ group :development, :test do
   gem 'puppetlabs_spec_helper',  :require => false
   gem 'puppet-lint', '>= 1.1.0', :require => false
   gem 'puppet-syntax',           :require => false
-  gem 'rspec-puppet', '~> 2.0.0', :require => false
+  gem 'rspec-puppet', '~> 2.1.0', :require => false
 end
 
 group :beaker do