Convert search_remote_tap test to spec.

Library/Homebrew/test/cmd/search_remote_tap_spec.rb

@@ -0,0 +1,19 @@
+require "cmd/search"
+
+describe Homebrew do
+  specify "#search_tap" do
+    json_response = {
+      "tree" => [
+        {
+          "path" => "Formula/not-a-formula.rb",
+          "type" => "blob",
+        },
+      ],
+    }
+
+    allow(GitHub).to receive(:open).and_yield(json_response)
+
+    expect(described_class.search_tap("homebrew", "not-a-tap", "not-a-formula"))
+      .to eq(["homebrew/not-a-tap/not-a-formula"])
+  end
+end

Library/Homebrew/test/search_remote_tap_test.rb

@@ -1,19 +0,0 @@
-require "testing_env"
-require "cmd/search"
-
-class SearchRemoteTapTests < Homebrew::TestCase
-  def test_search_remote_tap
-    json_response = {
-      "tree" => [
-        {
-          "path" => "Formula/not-a-formula.rb",
-          "type" => "blob",
-        },
-      ],
-    }
-
-    GitHub.stubs(:open).yields(json_response)
-
-    assert_equal ["homebrew/not-a-tap/not-a-formula"], Homebrew.search_tap("homebrew", "not-a-tap", "not-a-formula")
-  end
-end