Fix non ES5 compliant regexp
Fix non ES5 compliant regexp

ES5 appears to require that { be escaped when not used as part of a quantifier. While this works fine in browsers it appears to choke less lenient runtimes (e.g. Duktape).
chaijs/chai,meeber/chai,lucasfcosta/chai,lucasfcosta/chai,chaijs/chai,meeber/chai