GET retrieves available EVN Modes

Given I am authenticated as Customer K0002
When I send /api/customers/K0002/evn-modes
Then I should receive HTTP/1.1 200 OK
with following body

{
  "href": "/api/customers/K0002/evn-modes",
  "items": [{
    "href": null,
    "links": [],
    "data": [{
      "name": "name",
      "value": "NEVER"
    }]
  }, {
    "href": null,
    "links": [],
    "data": [{
      "name": "name",
      "value": "SHORTEN"
    }]
  }, {
    "href": null,
    "links": [],
    "data": [{
      "name": "name",
      "value": "FULL"
    }]
  }],
  "links": null
}

Missing Customer

Given I am authenticated as Admin
When I send /api/customers/K404/evn-modes
Then I should receive HTTP/1.1 404 Not Found
And Content-Type header should be
with following body:

{
  "title": "Customer not found",
  "detail": "Customer with identifier K404 has not been found",
  "described_by": "http://api.nfon.net/probs/customer-not-found"
}

Service Portal REST API

GET /api/customers/{customer_id}/evn-modes