Add Zayo networks

[duncandewhurst]

Lot of network maps here, with some interesting details: https://www.zayo.com/network/

[duncandewhurst]

There are some older KMZ files available here, I haven't looked into them: https://web.archive.org/web/20140807071618/http://www.zayo.com/network/network-file-downloads/

[duncandewhurst]

Various ArcGIS datasets here: https://www.arcgis.com/home/search.html?restrict=false&sortField=relevance&sortOrder=desc&searchTerm=tags%3A%22ZAYO%22#content