Add packager tests (#120)

* Remove unused code

* Test vendored_pin_for

test/packager_test.rb

@@ -35,10 +35,6 @@ def code() "200" end
   end
 
   test "failed request with mock" do
-    response = Class.new do
-      def code() "500" end
-    end.new
-
     Net::HTTP.stub(:post, proc { raise "Unexpected Error" }) do
       assert_raises(Importmap::Packager::HTTPError) do
         @packager.import("[email protected]")
@@ -54,4 +50,9 @@ def code() "500" end
   test "pin_for" do
     assert_equal %(pin "react", to: "https://cdn/react"), @packager.pin_for("react", "https://cdn/react")
   end
+
+  test "vendored_pin_for" do
+    assert_equal %(pin "react" # @17.0.2), @packager.vendored_pin_for("react", "https://cdn/[email protected]")
+    assert_equal %(pin "javascript/react", to: "javascript--react.js" # @17.0.2), @packager.vendored_pin_for("javascript/react", "https://cdn/[email protected]")
+  end
 end