Format: golang is not working properly

If I use `format: golang`, the report flattens all of my files. If I then click on a file to examine their coverage, I get the error

```
The file ... isn't available on github. Either it's been removed, or the repo root directory needs to be updated.
```

Because of the flattening, some files no longer appear in the report when another file with the same name exists in a different directory.