Only Sandbox environment is available

Currently the only environment available is Sandbox, in case we want to move to production environment there is no way of doing that:
```
const settings = {
    API_VERSION: "V2",
    SANDBOX_BASEURL: "https://gw-apic-gov.gazt.gov.sa/e-invoicing/developer-portal",
    PRODUCTION_BASEURL: "TODO"
};
```