Get a list of customers

curl --request GET \
  --url https://sandbox.gateway.sezzle.com/v2/customer \
  --header 'Authorization: <api-key>'

[
  {
    "uuid": "a9d8e15c-5e4a-4201-aa8f-7540f934a9a2",
    "expiration": "2020-04-28T17:58:11Z",
    "links": [
      {
        "href": "https://gateway.sezzle.com/v2/customer/a9d8e15c-5e4a-4201-aa8f-7540f934a9a2",
        "method": "GET",
        "rel": "self"
      },
      {
        "href": "https://gateway.sezzle.com/v2/customer/a9d8e15c-5e4a-4201-aa8f-7540f934a9a2",
        "method": "DELETE",
        "rel": "self"
      },
      {
        "href": "https://gateway.sezzle.com/v2/customer/a9d8e15c-5e4a-4201-aa8f-7540f934a9a2/preapprove",
        "method": "POST",
        "rel": "preapprove"
      },
      {
        "href": "https://gateway.sezzle.com/v2/customer/a9d8e15c-5e4a-4201-aa8f-7540f934a9a2/order",
        "method": "POST",
        "rel": "order"
      }
    ]
  }
]