mapdeck 0.2

• different palettes for both stroke & fill options
• stroke_colour fix for polygons
• transitions argument for most layers
• mapdeck() argument order changed so data is first ( to work better with pipes )
• update_view and focus_layer added to focus layers on data
• bearing and pitch maintained on data layer updates
• bearing argument to mapdeck()
• add_geojson() fully supported
• add_sf() convenience function
• Z attributes supported
• MULTI-geometry sf objects supported
• can use variables in place of string arguments
• highlight_colour argument
• all add_*() functions migrated to c++
• layer_id is optional to the user
• auto_highlight argument