Senior goaltender Christoffer Hernberg had 26 saves against Merrimack on Saturday night. (Matt Dwyer/Connector) Hannah Manning Connector Editor NORTH ANDOVER — The first fifty-nine minutes of the UMass Lowell-Merrimack game was back-and-forth, almost tedious hockey. The last minute of regulation was chaos. And overtime was pandemonium. The 14th-ranked UMass Lowell men’s hockey team skated to…