Donning safety glasses, closed-toe shoes and rubber gloves, three bankers recently received a lesson in brewing beer. Exhibit ‘A’ Brewing in Framingham, Mass., hosted two marketing managers and a summer intern from Avidia Bank in Hudson, Mass., as part of a collaboration between the companies. The result of last month's brew session is Demo Tape 19: Liquid Tender, an India pale ale that will debut at the brewery on July 21 during an event sponsored by the mutual.