Use median file covered_strength for project covered_strength to mitigat...

...e outliers.
Sorry.  I had fixed the test, but then I had to redo it because I didn't make a branch in my clone.  And I forgot to do the test change in the new branch.  Should I start over?  I was thinking that even though we won't have the lines of code divide by 0 problem, perhaps it still makes sense to consider covered strength to be 0 if there are no lines of code, and I think the array would be empty, no?  Perhaps I should check for empty array instead?