Fix: MSTestExecutor.GetTestResult() throws exception if no duration attribute exists.
Fix: MSTestExecutor.GetTestResult() throws exception if no duration attribute exists.

OpenCoverUI/OpenCover.UI,MelleKoning/OpenCover.UI,cygi/OpenCover.UI,pavzaj/OpenCover.UI,pver/OpenCover.UI,joshlrogers/OpenCover.UI,bigmat/OpenCover.UI