fix the :test rake task

which I broke when I yanked Hoe

Rakefile

@@ -1,5 +1,3 @@
-require "rubygems"
-
 require "hoe/markdown"
 Hoe::Markdown::Standalone.new("loofah").define_markdown_tasks
 
@@ -9,6 +7,13 @@ Concourse.new("loofah", fly_target: "ci") do |c|
   c.add_pipeline "loofah-pr", "loofah-pr.yml"
 end
 
+require "rake/testtask"
+Rake::TestTask.new do |t|
+  t.libs << "test"
+  t.test_files = Dir["test/**/*.rb"]
+end
+task :default => :test
+
 desc "generate safelists from W3C specifications"
 task :generate_safelists do
   load "tasks/generate-safelists"
@@ -27,5 +32,3 @@ task :debug_manifest do
   spec = eval(File.read("loofah.gemspec"))
   puts spec.files
 end
-
-task :default => :test

test/helper.rb

@@ -1,7 +1,6 @@
-require "rubygems"
+require "minitest/autorun"
 require "minitest/unit"
 require "minitest/spec"
-require "minitest/autorun"
 require "rr"
 
 require File.expand_path(File.join(File.dirname(__FILE__), "..", "lib", "loofah"))