Allow provisioning to Amazon linux

libmachine/provision/amzn.go

+package provision
+
+import (
+	"github.com/docker/machine/libmachine/drivers"
+)
+
+func init() {
+	Register("Amazon Linux 2", &RegisteredProvisioner{
+		New: NewAmazonLinuxProvisioner,
+	})
+}
+
+func NewAmazonLinuxProvisioner(d drivers.Driver) Provisioner {
+	return &AmazonLinuxProvisioner{
+		NewRedHatProvisioner("amzn", d),
+	}
+}
+
+type AmazonLinuxProvisioner struct {
+	*RedHatProvisioner
+}
+
+func (provisioner *AmazonLinuxProvisioner) String() string {
+	return "amzn"
+}