Update memcached Docker tag to v1.6.14 (#88)

Co-authored-by: Renovate Bot <[email protected]>

Author: renovate[bot]

definition/docker-compose.yml

@@ -65,7 +65,7 @@ services:
         restart: unless-stopped
 
     memcached:
-        image: 'memcached:1.6.12'
+        image: 'memcached:1.6.14'
         ports:
             - '11211'
         restart: unless-stopped