Merge pull request #2141 from reitermarkus/spec-outdated

Convert `brew outdated` test to spec.

Library/Homebrew/test/outdated_test.rb → Library/Homebrew/test/cmd/outdated_spec.rb

-require "testing_env"
-
-class IntegrationCommandTestOutdated < IntegrationCommandTestCase
-  def test_outdated
+describe "brew outdated", :integration_test do
+  it "prints outdated Formulae" do
     setup_test_formula "testball"
     (HOMEBREW_CELLAR/"testball/0.0.1/foo").mkpath
 
-    assert_equal "testball", cmd("outdated")
+    expect { brew "outdated" }
+      .to output("testball\n").to_stdout
+      .and not_to_output.to_stderr
+      .and be_a_success
   end
 end