build(css) fix missing dist/select.css

Resolves bad changes made in #1541 which caused no select.css to be
generated as part of the build.

Author: user378230

gulpfile.js

@@ -80,6 +80,7 @@ gulp.task('styles', ['clean'], function() {
       timestamp: (new Date()).toISOString(), pkg: config.pkg
     }))
     .pipe($.concat('select.css'))
+    .pipe(gulp.dest('dist'))
     .pipe($.minifyCss())
     .pipe($.concat('select.min.css'))
     .pipe($.sourcemaps.write('../dist', {debug: true}))