This is how I installed memcached so it may have something to do with the problem:
sudo apt-get install memcached
sudo apt-get install gcc make autoconf libc-dev pkg-config
sudo apt-get install zlib1g-dev
sudo apt-get install libmemcached-dev
sudo pecl7.1-sp install memcached
Create a configuration file for the extension and restart PHP
sudo bash -c "echo extension=memcached.so > /etc/php7.1-sp/conf.d/memcached.ini"
sudo service php7.X-fpm-sp restart
Again THIS WORKS and memcached is working correctly within Laravel. When I run composer update now it spits out the error:
[Symfony\Component\Debug\Exception\FatalThrowableError]
Class 'Memcached' not found