Don't run knife plugin features on Chef 0.9.x.

Knife gained the ability to load plugins from gems in 0.10.0.

Rakefile

@@ -9,8 +9,9 @@ task :default => [:install, :spec, :features]
 Bundler.setup
 Bundler::GemHelper.install_tasks
 
+require 'chef'
 Cucumber::Rake::Task.new(:features) do |t|
-  t.cucumber_opts = "features --format pretty"
+  t.cucumber_opts = "features --format pretty#{' -t ~@requires_chef_10' if Chef::VERSION.start_with? '0.9.'}"
 end
 
 RSpec::Core::RakeTask.new

features/generate_placeholder_examples.feature

@@ -1,3 +1,4 @@
+@requires_chef_10
 Feature: Generate placeholder examples
 
   In order to encourage cookbooks to have examples