Convert GPG2Requirement test to spec.

Library/Homebrew/test/gpg2_requirement_spec.rb

@@ -0,0 +1,23 @@
+require "requirements/gpg2_requirement"
+require "fileutils"
+
+describe GPG2Requirement do
+  let(:dir) { @dir = Pathname.new(Dir.mktmpdir) }
+
+  after(:each) do
+    FileUtils.rm_rf dir unless @dir.nil?
+  end
+
+  describe "#satisfied?" do
+    it "returns true if GPG2 is installed" do
+      ENV["PATH"] = dir/"bin"
+      (dir/"bin/gpg").write <<-EOS.undent
+        #!/bin/bash
+        echo 2.0.30
+      EOS
+      FileUtils.chmod 0755, dir/"bin/gpg"
+
+      expect(subject).to be_satisfied
+    end
+  end
+end

Library/Homebrew/test/gpg2_requirement_test.rb

@@ -1,25 +0,0 @@
-require "testing_env"
-require "requirements/gpg2_requirement"
-require "fileutils"
-
-class GPG2RequirementTests < Homebrew::TestCase
-  def setup
-    super
-    @dir = Pathname.new(mktmpdir)
-    (@dir/"bin/gpg").write <<-EOS.undent
-      #!/bin/bash
-      echo 2.0.30
-    EOS
-    FileUtils.chmod 0755, @dir/"bin/gpg"
-  end
-
-  def teardown
-    FileUtils.rm_rf @dir
-    super
-  end
-
-  def test_satisfied
-    ENV["PATH"] = @dir/"bin"
-    assert_predicate GPG2Requirement.new, :satisfied?
-  end
-end