v2.0.0

• Migrated from CoffeeScript to ECMAScript 2015(-ish...). Only compatible from node v6, transform as necessary.
• (major) Removed undocumented parser option Parser#regex. If anyone wants to override the regex I use in this module, please submit an issue for your case.
• (major) Parser and renderer functions now return undefined instead of null in cases where it did before.
• (major) Parser now accepts input only from Parser#parse instead of the constructor and #text. The result of parse is now invariant among multiple calls to it.
• (major) #hasRuby has been removed. To check for ruby existence, check the hasRuby property of the returned array.