Include default center coordinates & zoom

• updates the latest version of non-empty styles with a default center & zoom
• updates testing to include node v10 & v12
• moves package under @mapbox namespace

Template styles only

• Remove deprecated styles: Emerald, Outdoors, Pencil
• Remove styles: Streets, Light, Dark
• Update sprites

Update of GL styles to use Mapbox Streets v7

Fixes fontstack and spritesheet references to Mapbox stack.

Update of GL styles to use Mapbox Streets v7

Merge pull request #256 from mapbox/symlink-satellite-v8

satellite style updated to mbsv7, ready to merge