Function parent

parent(path: string): string
Returns the parent directory of a path. If the input is an absolute root, returns the root itself
Parameters
- path: string
  The input path
Returns string
The normalized parent path, or root if input is root
Example
```
parent('foo/bar/baz') // returns 'foo/bar'
parent('c:/foo') // returns 'c:'
parent('c:/') // returns 'c:'
```