v6.0.0

Breaking changes:

• Add support for calc expressions (#140 by @nsaunders)

• Add table selector (#141 by @plurip-software)

• Update the box-shadow implementation (#88 by @vyorkin)

• Update project and deps to PureScript v0.15.0 (#156 by @JordanMartinez)

• Dropped almost all named colors (#156 by @JordanMartinez)

  These colors were originally defined in purescript-colors (i.e.
  one module per schema) because each schema should be defined as its
  own library. This change was propagated to this release.

New features:

• Add smart constructors for generic font families (#68, #136 by @Unisay and @JordanMartinez)
• Add support for text-direction (#83, #137 by @vyorkin and @JordanMartinez)
• Add outline and constituent properties (#145 by @nsaunders)
• Add support for visibility property (#148 by @nsaunders)

Other improvements:

• Added purs-tidy formatter (#138 by @thomashoneyman)
• Remove ending space in css output (e.g. padding: 1 2 3 4 ) (#135 by @chexxor and @JordanMartinez)