Add port: www/minio-client

Minio Client is a replacement for ls, cp, mkdir, diff and rsync
commands for filesystems and object storage.

WWW: https://minio.io/downloads/#minio-client

PR: 217124
Submitted by: jhixson@gmail.com
Approved by: mat (mentor)
Differential Revision: https://reviews.freebsd.org/D9642