I get "Option 'version' is unknown" if it comes after other user-defined options on the command line

Since `version` is pretty much built-in, it should never be "unknown", especially if this message is immediately followed by helptext that clearly shows that it is a valid option.

```
3676 ~/fork/foo-etl$ dotnet etl/bin/Debug/netcoreapp3.0/etl.dll -c foo -d bar --version
etl 0.0.1
Copyright (C) 2020 etl

ERROR(S):
Option 'version' is unknown.

-c, --configdir Required. Path to dir that contains client configurations

-d, --invoicedir Required. Path to dir that contains invoices are

--help Display this help screen.

--version Display version information.
```