A Roseville company that offers a restaurant reservation booking app raised nearly $600,000 in equity financing that it plans to use for marketing. SeatNinja has sold $550,000 worth of preferred stock since early September and $45,125 in common stock since August, according to registration documents filed Tuesday with the Securities and Exchange Commission. Since its launch in 2013, SeatNinja has developed a small but loyal customer base, said Michael Reinero, president of the company, one of its…