v7.0.0 - Catoctin Creek

Added

• Improved error handling of unsupported font file formats in the font-face
  mixin (supported formats are woff2 and woff).
• CSS var() and env() functions are now accepted as values in the
  position and size mixins.

Changed

• Updated thor from 0.x to 1.x

Removed

• The font-face mixin no longer supports ttf, svg, and eot
  font file formats.