[maven-release-plugin] prepare release v0.4.0-beta
[maven-release-plugin] prepare release v0.4.0-beta

mbosecke/pebble,PebbleTemplates/pebble,jcarvalho/pebble,DanStout/pebble,chambas/pebble,ebussieres/pebble,PebbleTemplates/pebble,samlanning/pebble,dotneet/pebble,hectorlf/pebble