Use ansi-terminal's new "hSupportsANSI" function

Re. https://github.com/feuerbach/ansi-terminal/issues/4, as fixed by https://github.com/feuerbach/ansi-terminal/commit/c7ed522d00442a7af1b0a0370eb2cc47cd532478 and now already used [elsewhere](https://github.com/feuerbach/tasty/commit/6f0e0a3f1050659ef9241af179da35453676d61d).