Update version number in README
Update version number in README

shtouff/vagrant-debian-jessie-64,code-kitchen/vagrant-debian-jessie-64,dforsber-p/vagrant-debian-jessie-64,kraksoft/vagrant-box,jstuyts/vagrant-jessie-minimal-amd64-customizable,Gasol/vagrant-debian-jessie-64,dotzero/vagrant-debian-jessie-64,xezpeleta/vagrant-debian-jessie-64,nvtkaszpir/vagrant-box