1.1.0

• Updated csstree to 1.0.0-alpha20
• Changed validate function to always contain a list of errors (no single error on parse error)
• Added validateDictionary() that validate a dictionary, where key is a filename and value is a CSS as string
• Changed validateFile(), validatePath() and validatePathList() to handle possible file system exceptions (such errors will be stored as regular errors)
• Added second argument for validatePath() and validatePathList() to rule which file should be validated. Functions validate files with .css extension only, when second parameter is not passed.
• Fixed minor issues in reporters output