AUGUSTA — As the race for Maine’s next governor shifts from primary contests to the general election, voters will be hearing a lot about Janet Mills, the Democrat, and Shawn Moody, the Republican. But the primary victories by Mills and Moody also mean voters are sure to hear a lot about the outgoing governor – the Republican firebrand who reshaped Maine’s conservative brand and imprinted a combative tone on state politics. “To some extent, some of this is a referendum on Paul LePage’s eight years as governor,” said James Melcher, a political science professor at the University of Maine at Farmington. Melcher said he expects a close contest, especially with two fairly well-known independent candidates, Terry Hayes and Alan Caron, also on the ballot.