Allow comma characters in parser

I discovered this while testing [Standard Clojure Style](https://github.com/oakmac/standard-clojure-style-js/) against the [metabase codebase](https://github.com/metabase/metabase). Specifically, [this line](https://github.com/metabase/metabase/blob/05c2fb221d01bc09615a82da8a695cb32992fde9/src/metabase/query_processor/streaming/csv.clj#L43). See also: - [Issue #63](https://github.com/oakmac/standard-clojure-style-js/issues/63) - [PR-64](https://github.com/oakmac/standard-clojure-style-js/pull/64/files)