[Feature Request] Allow multiple clients_config files

[hegyre]

Hello,

As per readme, a configuration directory can be used (which is the default for CentOS which is my distribution)

Currently the formula allows managing only one clients_config file, so that if I want to have 2 differents services with 2 different auto-logins, then I cannot.

We could create multiple extra conf file (with username and password inside) that can be then used for each service/script we need.

For example, I use the following for logrotate service ONLY:

  clients_config:
    # The formula does not currently (2019-03-13) allow us to create multiple clients_config files, so we are stuck with only one service user
    file: mysql-clients-logrotate.cnf
    sections:
      mysqladmin:
        user    : s-logrotate
        password: mypass

I'll then use my logrotate script with:
/usr/bin/mysqladmin --defaults-extra-file=/etc/my.cnf.d/mysql-clients-logrotate.cnf --local flush-slow-log

If I want to use another script, then I'd like to create another /etc/my.cnf.d/mysql-clients-serviceX.cnf which contains other credentials