CRAN version 0.2.0

• Added snap_interval to ms_simplify() (#43, @nikolai-b)
• Bugfix: Respect drop_null_geometries argument in ms_simplify.geo_list() (#45, @nikolai-b)
• Add Kent Russell (@timelyportfolio) to authors list for his JavaScript expertise and advice
• Add Matthew Bloch (@mbloch) to authors list as mapshaper copyright holder
• Update mapshaper to version 0.3.41
• A V8 session is now launched once per function call and destroyed when the function exits, rather than created on package load and retained for the entire session (#49)
• Column classes are now restored after being sent through mapshaper functions (#46)
• Fixed a bug where very small values of keep in ms_simplify() were converted to scientific notation (#48)
• Added weighting argument to ms_simplify() (#27)
• Added remove_slivers argument in ms_clip() and ms_erase()