Bump version to 1.5.7
Bump version to 1.5.7

mattwoberts/pushd,Yu-Qiu/test-pushd,Suninus/pushd,Suninus/pushd,steedos/opush,rs/pushd,peleccom/pushd,chobiwa/pushd,futurice/pushd,Product-Foundry/pushd,steedos/pushd,vedharish/pushd,steedos/pushd,Product-Foundry/pushd,futurice/pushd,Binarypark/pushd,avqdev/pushd,Yu-Qiu/test-pushd,vedharish/pushd,peleccom/pushd,mattwoberts/pushd,skishore23/Charakapush,steedos/opush,rs/pushd,steedos/pushd,avqdev/pushd,skishore23/Charakapush,4screens/pushd,4screens/pushd,steedos/opush,chobiwa/pushd,Binarypark/pushd