Steps to reproduce the issue

I changed my configuration.php file to include the following to use Memcached:
public $caching = '2';
public $cache_handler = 'memcache';
public $memcache_server_host = 'memcached-10314.c2.eu-west-1-3.ec2.cloud.redislabs.com';
public $memcache_server_port = '10314';
public $memcache_server_user = 'memcached-app98811975';
public $memcache_server_pass = '********';
I have installed the memcached extension on Heroku, and it was set up automaticly. I received the details above, so I entered the host I received and the port. There was also a username and password given to me, and I did not find how to enter this in the configuration.php so I added as seen above here. Is this maybe where I'm wrong?

Expected result

I expected the caching to be done by Memcached and to not receive an error.

Actual result

Now I get a server 500 error on my heroku webserver, and the following error:
The memcache Cache Storage is not supported on this platform.

System information (as much as possible)

• php (7.2.6)
  • ext-gd (bundled with php)
  • nginx (1.8.1)
  • apache (2.4.33)

Additional comments