Get a user

curl --request GET \
  --url https://api.shiftkeeper.io/users/{user_id} \
  --header 'x-api-key: <api-key>'

{
  "user": {
    "id": "usr_bq7CmsOKLmkMeZkUUu1hy",
    "name": "Rick",
    "email": "rick@example.org",
    "time_zone": "Europe/Paris",
    "role": "owner",
    "seat": "member",
    "slack_id": "U082KENSEQ3"
  }
}