Update to newer cucumber and aruba

middleman-cli/lib/middleman-cli/templates/extension/Gemfile

@@ -13,7 +13,6 @@ end
 
 group :test do
   gem 'cucumber'
-  gem 'fivemat'
   gem 'aruba'
   gem 'rspec'
 end

middleman-cli/lib/middleman-cli/templates/extension/Rakefile

@@ -4,7 +4,7 @@ Bundler::GemHelper.install_tasks
 require 'cucumber/rake/task'
 
 Cucumber::Rake::Task.new(:cucumber, 'Run features that should pass') do |t|
-  t.cucumber_opts = "--color --tags ~@wip --strict --format #{ENV['CUCUMBER_FORMAT'] || 'Fivemat'}"
+  t.cucumber_opts = "--color --tags ~@wip --strict"
 end
 
 require 'rake/clean'