There was reason for apprehension when John Porter quit his job at Century Electric and decided to start his own roofing business.That was back in 1978.“Like most roofing companies, I started from the back of a pickup,” said John. “It was me and a couple guys helping me.”Porter probably never dreamed at the time his upstart company would climb to the highest rooftop and one day land the contract to install the roof on the Atlanta Falcons’ new stadium.The stadium, with a price tag of $1.5 billion, is under construction about 100 feet from the Georgia Dome. It’s been named Mercedes-Benz Stadium and has its own website where it’s billed as “the finest sports and entertainment facility in the world.”So how did a once-tiny, McMinnville-based company land the massive job to roof what will be the grandest stadium in the Southeast?