While attempting to import an .sql file I experienced the following error Unknown collation: 'utf8mb4_unicode_520_ci'. It turns out the CentOS 7 repo only offers MariaDB version 5.5, meanwhile www.mariadb.org currently offers version 10.1 and also states that utf8mb4_unicode_520_ci is a supported collation...

SOLUTION:

sudo echo “
#MariaDB 10.1 CentOS repository list - created 2016-08-19 03:23 UTC
#http://downloads.mariadb.org/mariadb/repositories/
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.1/centos7-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1
“ > /etc/yum.repos.d/MariaDB.repo
sudo yum update

Now MariaDB is fully updated and supports utf8mb4_unicode_520_ci collation and I was able to import the sql file.