prep for CRAN initial release

[timelyportfolio]

leaflet.extras would be even awesomeR if on CRAN. If possible, I would love to see it hit CRAN before useR 2017, which would also mean mapedit could release prior to useR. I will volunteer to do the early prep work and track at forked branch.

checklist from CRAN check

• reduce size < 5mb
  treemap
  sunburst
  * rbuildignore virginia.rds - delete? timelyportfolio@4a41a62
  * delete mapshaper.js and turf.js since I see no dependencies on these timelyportfolio@25d706e
• undocumented arguments timelyportfolio@11762c7

cc @tim-salabim

[timelyportfolio]

After completing the checklist above, passes local CRAN check and rhub::check_for_cran().

[bhaskarvk]

Working on this now, will submit to CRAN before EOD. Thanks so much for taking a lead on this.

[bhaskarvk]

Submitted to CRAN. Fingers crossed!