run the follwoing as root
apt-get install -y --allow-downgrades --allow-remove-essential --allow-change-held-packages \
php7.0-cli php7.0-dev \
php7.0-pgsql php7.0-sqlite3 php7.0-gd \
php7.0-curl php7.0-memcached \
php7.0-imap php7.0-mysql php7.0-mbstring \