React Tippy (opallabs)

Major changes:

• tippy.js is now a true dependency (rather than a full copy of the source code)
  • Requires tippy.js@2.x, react@16.x
  • See tippy.js docs for the list of all props/options
• html prop has been renamed to content (can be a function or React element); React Portal is used behind the scene to render the tooltip's content