GOP rock star Scott Brown’s victory train rolled into Southie last night where the senator-elect hoisted a frosty beer with a local radio host to live up to one his first campaign promises. “We made a bet and they said if they endorsed me and I won then we’d have to get together for a few beers,” Brown, a Wrentham Republican, said at The Stadium in South Boston last night. “After it was over, they called and reminded me.” Brown, who drove himself to the pub in his now-legendary green GMC Canyon truck, turned the beer summit with WAAF [website]-FM...