Pass non-empty commit author details in transliteration test

Empty name or email are not allowed by libgit2 and cause a test failure
when the test suite is run against rugged_adapter.

test/test_unicode.rb

@@ -91,7 +91,7 @@ context "Frontend Unicode support" do
 
   test 'transliteration' do
     # TODO: Remove to_url once write_page changes are merged.
-    @wiki.write_page('ééééé'.to_url, :markdown, '한글 text', { :name => '', :email => '' })
+    @wiki.write_page('ééééé'.to_url, :markdown, '한글 text', commit_details)
     page = @wiki.page('eeeee')
     assert_equal '한글 text', utf8(page.raw_data)
   end