updates code to be compatible with:
- github.com/minio/mc v0.0.0-20200415193718-68b638f2f96c
- github.com/minio/minio v0.0.0-20200415191640-bde0f444dbab
Note: admin_config api is patched temporarily now to
return the target configuration as a raw string due to the
changes done on minio.