https://github.com/andyjohnson/CMI-5_Spec_Current/blob/master/v1/CourseStructure.xsd incorrect path to XSD

[nphoenix]

Shoudl it be https://w3id.org/xapi/profiles/cmi5/v1/CourseStructure.xsd instead of http://www.adlnet.gov/cmi5/CourseStructure.xsd