UPGRADE.md

UPGRADE FROM 1.0.0-beta.17 to 1.0.0-beta.18

• Customer registration payload changed:

  {
  -  "user": {
  -    "plainPassword": {
  -      "first": "foobar",
  -      "second": "foobar"
  -    }
  -  }
  +  "plainPassword": "foobar",
  +  "channel": "CHANNEL_CODE"
  }