added preinstall script for mean.json
added preinstall script for mean.json

dantix/meanio,ssmlee04/meanio,timelf123/meanio,SibuStephen/mean-cli,AMI-NTBU/meanio,ADSKLowenthal/meanio,SibuStephen/mean-cli,Jeff-Lewis/mean-cli,lvarayut/meanio,SibuStephen/mean-cli,rjVapes/meanio,ideawake/meanio,dantix/meanio,Jeff-Lewis/mean-cli,Jeff-Lewis/mean-cli,KaySchneider/meanio4,mmind-hub/meanio,timelf123/meanio,ideawake/meanio,kwakuzigah/meanio,KaySchneider/meanio4,ssmlee04/meanio,linnovate/mean-cli,AMI-NTBU/meanio,lvarayut/meanio,Jeff-Lewis/meanio,linnovate/meanio,kwakuzigah/meanio,rjVapes/meanio,mmind-hub/meanio,rospogeo/meanio,rospogeo/meanio,linnovate/mean-cli,linnovate/meanio,Jeff-Lewis/meanio,linnovate/mean-cli,garyxu1987/tower