highcharter 0.3.0

• Igraph support to hchart (#61)
• New function export_hc. Take a highchart object and
  write a js file with the options (#60).
• New function tooltip_table. Helper to create table based
  in tags from htmltoolspackage #59).
• New function hc_colors. Function for the colors option in
  highcharts api (#57).
• Adding funnel.js and gauge-solid.js to depedenci for create
  funnel charts and charts like apple watch (#56).
• The hc_themes_... functions gains a ... parameter to
  add styles to the current invoked theme (#53).
• More themes: flat, flatdark, smpl, ft (financial times) (#49).
• Dont run error (\dontrun{}) to avoid quantmod package example
  in flags function