Create Push Registration

curl https://api.thanxsandbox.com/push_registrations \
  -X PUT \
  $AUTH_HEADERS
  -d '{
    "push_registration": {
      "device_type": "ios",
      "token": "wourdweroi238432423425fsgd"
    }
  }'

{
  "push_registration": {
    "token": "wourdweroi238432423425fsgd",
    "device_type": "ios"
  }
}