I was having a bit of trouble with this so I thought I would write a quick post on how to set this up. If you have a local vagrant that is running something like 5.6 and you need to update to 7 here are the steps you have to take.
SSH into your vagrant.
run these commands:
sudo apt-get install -y language-pack-en-base sudo LC_ALL=en_US.UTF-8 add-apt-repository ppa:ondrej/php sudo apt-get update sudo apt install php libapache2-mod-php sudo a2dismod php5 sudo a2enmod php7.1 sudo apt-get install php7.1-mysql sudo apt-get install php7.1-xml sudo service apache2 restart
Then for the xdebug part I found this particular article very helpful.
This article may also help you on your travels.