syntax error with 'gulp clean' - clone and install

[rowntreerob]

--updated --
workaround
commit/0eb960cff1c7fee021f9c67b9a484248accf51ae works fine . this module's syntax OK

application-shell$ gulp --version
[11:27:13] CLI version 3.9.1
[11:27:13] Local version 3.9.1

rob@ application-shell$ gulp clean
/home/rob/tmp/application-shell/gulp-tasks/service-worker.js:57
.catch(() => {
^
SyntaxError: Unexpected token )
at exports.runInThisContext (vm.js:73:16)
at Module._compile (module.js:443:25)
at Object.Module._extensions..js (module.js:478:10)
at Module.load (module.js:355:32)
at Function.Module._load (module.js:310:12)
at Module.require (module.js:365:17)
at require (module.js:384:17)
at requireDir (/home/rob/tmp/application-shell/node_modules/require-dir/index.js:116:33)
at Object. (/home/rob/tmp/application-shell/gulpfile.js:40:23)
at Module._compile (module.js:460:26)

--- i have no idea why it does not like that syntax ..