Alleging she was duped into hiring a substandard roofer for residential repairs because it had “Master Elite” certification from GAF Materials Corp., Sarah Mabry accused GAF of engaging in unfair and deceptive practices that violated the Illinois Consumer Fraud Act based on a Federal Trade Commission regulation — part of its “Guides Concerning Use of Endorsements and Testimonials in Advertising” — that requires disclosure of any “connection between the endorser and the seller of …