It currently doesn't and unfortunately I don't have time to port it at the moment. Might not be ported before summer. Looks like scaraman did a quick port, see here https://forum.pjrc.com/threads/43491-New-Stepper-Motor-Library?p=233648&viewfull=1#post233648.
Actually I'm working on it but it will take some time (it currently is not on my priority list). Meanwhile here is some information about a workaround (never tested it)