Varargs support

[phlmn]

Hey folks, thanks for this library!

I just experienced an error. When using the varargs syntax the following error occurs:

Error: Selector ("class") expected "identifier" or "interpolation" (1:28)
    at InputStream.err (dist/input-stream.js:122:13)
    at Object.err (dist/input-stream.js:161:20)
    at TokenStream.err (dist/token-stream.js:297:40)
    at Object.err (dist/token-stream.js:634:20)
    at Parser.parse_selector (dist/parse.js:728:21)
    at dist/parse.js:435:25
    at Parser.maybe_function (dist/parse.js:609:14)
    at Parser.parse_atom (dist/parse.js:420:19)
    at Parser.parse_expression (dist/parse.js:394:25)
    at Parser.parse_arguments (dist/parse.js:581:37)
    at Parser.parse_at_rule (dist/parse.js:665:27)
    at Parser.parse_node (dist/parse.js:350:36)
    at Parser.parse_stylesheet (dist/parse.js:267:25)
    at module.exports (dist/parse.js:748:17)
    at parse (dist/index.js:27:10)

This is the source scss file, it's from Bootstrap 4:

@mixin box-shadow($shadow...) {
  @if $enable-shadows {
    box-shadow: $shadow;
  }
}

Are varargs just not support yet, or is this a bug?

Cheers, Philipp

[theKashey]

Related #20