0.3.0

Version 0.3.0

- Support not-nullable types, nested comments, unicode identifiers,
  backticked function names, comments in strings and more
- Add support for syntax highlighting queries
- Add C bindings
- Add scanner

Thanks to @returntocorp, @bricka, @brandonspark, @mattmassicotte,
@Wilfred, @Gh0u1L5, @HerringtonDarkholme, @amaanq, @SalBakraa and all
other contributors for your contributions!