Errors when running after first time in cross-dep bins workspaces

| Title | Description
| --------------------|------------
| Version | v0.23.2
| Type | Issue
| node | v10.15.0
| Operating System | MacOS Mojave (10.14.4)
| Short Description | `bolt` errors when running after the first time in cross-dep bins workspaces.
| Detailed description | The original issue was that `bolt` didn't manage cross dependencies binary files (#126) and was fixed in #191. However, even `bolt` now creates the symlink, a second run will fail with the error below this table.

_NOTE: Keep in mind that I'm also replicating this error via running `bolt` internal tests._

```sh
Error: EEXIST: file already exists, symlink '../../../bar/bin.js' -> '/private/var/folders/m3/hdz1bgz94vz5rc3x16gm7jr80000gn/T/0fd44005f5f3b1950271e2eff9b65abc/workspace-with-bin/packages/foo/node_modules/.bin/bar'
```

Start by reproducing the second run in the Bolt internal tests using the cross-dependency bins workspace described in the issue. Inspect the existing symlink handling and verify that rerunning Bolt does not fail with EEXIST when the link already exists.

Written by the indexing model from the issue text.