Output information about issue created for forward merge

See gh-16458

git/hooks/forward-merge

@@ -82,5 +82,6 @@ username = config['github']['credentials']['username']
 password = config['github']['credentials']['password']
 dry_run = config['dry_run']
 new_issue_number = create_issue(username, password, repository, forward_merge.issue, title, labels, milestone, dry_run)
+puts "Created gh-#{new_issue_number} for forward merge of gh-#{forward_merge.issue} into #{forward_merge.milestone}"
 rewritten_message = forward_merge.message.sub(forward_merge.line, "Closes gh-#{new_issue_number}")
 File.write(message_file, rewritten_message)