func Unmarshal(in []byte, out interface{}) error {
	var res interface{}
	if err := yaml.Unmarshal(in, &res); err != nil {
		return err
	}
	*out.(*interface{}) = cleanupMapValue(res)
	return nil
}
Unmarshal YAML to map[string]interface{} instead of map[interface{}]interface{}.
package yaml
import (
	"fmt"
	"gopkg.in/yaml.v2"
)