Add a unit test

app_test.rb

@@ -0,0 +1,19 @@
+ENV['APP_ENV'] = 'test'
+
+require './app'
+require 'test/unit'
+require 'rack/test'
+
+class ToyTest < Test::Unit::TestCase
+  include Rack::Test::Methods
+
+  def app
+    Sinatra::Application
+  end
+
+  def test_root
+    get '/'
+    assert last_response.ok?
+    assert_equal "hello there!\n", last_response.body
+  end
+end