6.0.0

• Added: at-rule-name-case rule.
• Added: at-rule-semicolon-newline-after rule.
• Added: function-name-case rule.
• Added: property-case rule.
• Added: selector-pseudo-class-case rule.
• Added: selector-pseudo-element-case rule.
• Added: selector-type-case rule.
• Added: unit-case rule.
• Added: unit-no-unknown rule.