update .travis.yml, see http://stackoverflow.com/questions/26488015/class-file-for-android-support-v4-widget-drawerlayoutimpl-not-found-on-travis-su
update .travis.yml, see http://stackoverflow.com/questions/26488015/class-file-for-android-support-v4-widget-drawerlayoutimpl-not-found-on-travis-su

a642500/Ybook,a642500/Ybook