Six Mainers of diverse backgrounds from all over the state each took their turn signing an application in Augusta today to begin gathering signatures for a citizen-initiated referendum to raise the minimum wage. The referendum, intended for the 2016 ballot, would see the minimum wage in Maine raised from $7.50 an hour to $9 an hour in 2017 and then by a dollar a year until 2020, when it would reach $12 an hour and then be indexed to the cost of living in future years.