"stats" always shows 0 "Lines of Test"

The Stats ("Lines of Code/Tests Metric Results") page seems to always shows 0 "Lines of Test".

This seems to be an apparent bug in `code_metrics` (see https://github.com/bf4/code_metrics/issues/12), and not `metric_fu`, but I figured it might also be a good idea to post an issue here just in case anyone else comes across the same problem, or to track the upstream issue.
