This morning Fast, a startup that provides online checkout and identity products, announced that it has closed a $102 million Series B. The new funding event was led by Stripe, a previous investor in Fast. Stripe, an online payments giant, also led Fast’s Series A last year, a deal worth $20 million. Fast has raised $124 million to date, it said in a release. TechCrunch reached out to Fast for comment regarding its growth pace. The company shared that gross merchandise volume (GMV) processed by its checkout service has “more…