Delete unused test directory

Until we're actually using the little helpers and scaffolding code,
let's just not have the clutter!

test/performance/browsing_test.rb

@@ -1,9 +0,0 @@
-require 'test_helper'
-require 'rails/performance_test_help'
-
-# Profiling results for each test method are written to tmp/performance.
-class BrowsingTest < ActionDispatch::PerformanceTest
-  def test_homepage
-    get '/'
-  end
-end

test/test_helper.rb

@@ -1,13 +0,0 @@
-ENV["RAILS_ENV"] = "test"
-require File.expand_path('../../config/environment', __FILE__)
-require 'rails/test_help'
-
-class ActiveSupport::TestCase
-  # Setup all fixtures in test/fixtures/*.(yml|csv) for all tests in alphabetical order.
-  #
-  # Note: You'll currently still have to declare fixtures explicitly in integration tests
-  # -- they do not yet inherit this setting
-  fixtures :all
-
-  # Add more helper methods to be used by all tests here...
-end