Colliding file names on mac OS due to the default case-insensitive filesystem

When I git clone on my Mac:

```
warning: the following paths have collided (e.g. case-sensitive paths
on a case-insensitive filesystem) and only one from the same
colliding group is in the working tree:

  'Sorts/SelectionSort.js'
  'Sorts/selectionSort.js'
```

You need to rename one of these files to avoid collision on case-insensitive filesystem