added support for _delay in query string to delay response of request on per request basis (#673)

* added support for passing _delay as query parameter to delay response by X milliseconds

* added tests / fixed linting error

src/server/router/plural.js

@@ -4,10 +4,12 @@ const pluralize = require('pluralize')
 const write = require('./write')
 const getFullURL = require('./get-full-url')
 const utils = require('../utils')
+const delay = require('./delay')
 
 module.exports = (db, name, opts) => {
   // Create router
   const router = express.Router()
+  router.use(delay)
 
   // Embed function used in GET /name and GET /name/id
   function embed(resource, e) {