AWS::ServiceCatalog::LaunchRoleConstraint.RoleArn not required (#1765)
AWS::ServiceCatalog::LaunchRoleConstraint.RoleArn not required (#1765)

https://github.com/cloudtools/troposphere/issues/1757
https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-servicecatalog-launchroleconstraint.html#cfn-servicecatalog-launchroleconstraint-rolearn
cloudtools/troposphere,cloudtools/troposphere