Added CKISubmission and CKIRubricAssessment support to CanvasKit
Added CKISubmission and CKIRubricAssessment support to CanvasKit

nlambson/CanvasKit,instructure/CanvasKit,instructure/CanvasKit,derrh/CanvasKit,instructure/CanvasKit,nlambson/CanvasKit,nlambson/CanvasKit,nlambson/CanvasKit,derrh/CanvasKit,instructure/CanvasKit,derrh/CanvasKit,derrh/CanvasKit