Can't have arrays of numbers unless using yaml source

[tomchipchase]

ENV and ini files don't have a native way to do Arrays of numbers.

This means, they are stored as strings with comma separators. However, there's nothing to indicate that the individual items should be converted to numbers when they are used.

This is not a problem for yaml sources as they can have native arrays of numbers.

Possibly need to add a second argument to the type, so that another converter can be used for each item in the Array.