Add new method GetObjectACL()

[pierre-emmanuelJ]

Example:

objInfo, err := minioClient.GetObjectACL("bucketName", "objectName")
if err != nil {
	return err
}

//object ACLs is in the Metadata header with stat details
fmt.Printf("%#v\n", "objInfo.Metadata")

[kannappanr]

Can you please add copyright info here.

[kannappanr]

The year has to be 2018

[nitisht]

Thanks for the PR @pierre-emmanuelJ . Do you mind adding a test here https://github.com/minio/minio-go/blob/master/functional_tests.go

You can add check like this https://github.com/minio/minio-go/blob/master/functional_tests.go#L293 so it runs only for S3 endpoints

[pierre-emmanuelJ]

@nitisht Do you want an example here ?

[nitisht]

@nitisht Do you want an example here ?

Yes, please. That'd be great

[kannappanr]

LGTM