allow specifying environment variable types other than string

[brendanlensink]

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[brendanlensink]

I'm not really sure if there's a good way to do this - I don't love the idea of having to include some kind of type information in the .env files, I kind of like how clean they are as just KEY=VALUE and worry it might end up snowballing into a nightmare to parse things.

I think adding some kind of automatic unwrapper that naively guesses what type the key should be might be more annoying than helpful if it's ever wrong, so maybe the 'official' suggestion is just to add an extension to your Environment object that unwraps to the correct type :/