Fix extra line that can occur on small outputs.

Sometimes the output can look like this: 
 
```
4.0K ─┬ 
 8.0K ─┬ .
 8.0K  └─┬ many
 4.0K    ├── hello_file
   0B    └── a_file

```
Instead of:
```
 8.0K ─┬ .
 8.0K  └─┬ many
 4.0K    ├── hello_file
   0B    └── a_file
```
This seems to be down to a call to:  e.path().ancestors()  in utils/mod.rs which can return '/' as an ancestor. 

Investigating. 
