Fix test to pass NodeJs 4
Fix test to pass NodeJs 4

NodeJS 4 seems to have arrowFunctions but not defaults in functions.

caolan/async,hargasinski/async,ecasilla/async,andalm/async,caolan/async,hargasinski/async,andalm/async,ecasilla/async,rlugojr/async,suguru03/async,suguru03/async,rlugojr/async