sauce_labs: use ["default"] instead of .default on config
sauce_labs: use ["default"] instead of .default on config

Hashr doesn't seem to handle the #default method call, possibly because
it is already defined on Hash and Hashr is a subclass of Hash.

ireznice/travis-worker,travis-ci/travis-worker,gavioto/travis-worker,final-ci/travis-worker,travis-ci/travis-worker,gavioto/travis-worker,ireznice/travis-worker,final-ci/travis-worker