empty path strings in outputs appear after some alignments

When running
```
deltacode -n tests/data/deltacode/ecos-failed-counts-assertion-new.json -o tests/data/deltacode/ecos-failed-counts-assertion-old.json -c ~/test.csv
```

Many modified or license change Deltas show an empty path value in our output. I believe this happens as a result of `align_scan()`, but I could be wrong. I will investigate further and post more details.