Do not use Babel's register hook in production

modules/server/StyleUtils.js

@@ -0,0 +1,9 @@
+import fs from 'fs'
+import path from 'path'
+import csso from 'csso'
+
+export const readCSS = (...args) =>
+  minifyCSS(fs.readFileSync(path.resolve.apply(path, args), 'utf8'))
+
+export const minifyCSS = (css) =>
+  csso.minify(css).css