add Mapbox Studio

This PR adds Mapbox Studio; however, I'm also looking for assistance as to how to resolve the following error before getting this merged:

```
==> Downloading https://mapbox.s3.amazonaws.com/mapbox-studio/mapbox-studio-darwin-x64-v0.1.0.zip
Already downloaded: /Library/Caches/Homebrew/mapbox-studio-0.1.0.zip
Error: It seems the symlink source is not there: '/opt/homebrew-cask/Caskroom/mapbox-studio/0.1.0/Mapbox Studio.app'
```