Update play-json to 3.1.0-M2#492

xuwei-k merged 1 commit intoscalapb-json:masterscalapb-json/scalapb-playjson:masterfrom

scala-steward-bot:update/play-json-3.1.0-M2scala-steward-bot/scalapb-playjson:update/play-json-3.1.0-M2Copy head branch name to clipboard