message: Added a fixed id for the first review, which is used in tests
diff: var db = require('./index')
  var reviews = [
  - { product: 1, message: 'One of my favorites!', author: 'admin@juice-sh.op' },
  + { _id: '3QxALD3cSdZ7ekW63', product: 1, message: 'One of my favorites!', author: 'admin@juice-sh.op' },
  { product: 17, message: 'Has a nice flavor!', author: 'bender@juice-sh.op' },
  { product: 3, message: 'I bought it, would buy again. 5/7', author: 'jim@juice-sh.op' },
  { product: 14, message: 'Fresh out of a replicator.', author: 'jim@juice-sh.op' },
  