testReportFileName-ing tweak
testReportFileName-ing tweak

enforcing file type, by appending an .xml extension if one doesn't exist.

garris/BackstopJS,klausbayrhammer/BackstopJS,klausbayrhammer/BackstopJS,garris/BackstopJS,cookchristopher/BackstopJS,cookchristopher/BackstopJS,garris/BackstopJS,mirzazeyrek/BackstopJS,mirzazeyrek/BackstopJS