added open module
added open module

xuan9/gulp-server-livereload,hiddentao/gulp-server-livereload,bolasblack/gulp-webserver,SteveBash/gulp-webserver,davidknezic/gulp-webserver,sanyueyu/gulp-webserver,bialikover/gulp-webserver,robertbaker/gulp-webserver,schickling/gulp-webserver,alexbuijs/gulp-server-livereload,mattraykowski/gulp-webserver