update php 7.3 debian 9

update_php_7.3_debian_9.txt

sudo apt install ca-certificates apt-transport-https
wget -q https://packages.sury.org/php/apt.gpg -O- | sudo apt-key add -
echo "deb https://packages.sury.org/php/ stretch main" | sudo tee /etc/apt/sources.list.d/php.list
sudo apt update
sudo apt install php7.3 php7.3-cli php7.3-common php7.3-curl php7.3-mbstring php7.3-mysql php7.3-xml php7.3-gd
sudo apt-get purge php7.0-common
sudo apt install phpmyadmin*
sudo a2enmod php7.3
sudo /etc/init.d/apache2  restart