fix: ensure nf-dotenv handles duplicate env variables

[clintval]

This turned out to be an issue in the underlying dotenv parser and was fixed in 3.2.0:

• Allow duplicate keys for variables cdimascio/dotenv-java#85

Closes #17

[TedBrookings]

I think this is okay, but I'd suggest maybe don't allow multiple definitions of the same environment. It feels like there's no good reason to have that and it's a likely bug. In my case, it was accidental and a bug. So I'd prefer the failure just with the improved error message.

[clintval]

I think this is okay, but I'd suggest maybe don't allow multiple definitions of the same environment. It feels like there's no good reason to have that and it's a likely bug. In my case, it was accidental and a bug. So I'd prefer the failure just with the improved error message.

Thanks! I realized I sent this in Slack but posting here so others can see the response:

I think because all the dotenv implementations I can find, and bash too, allow for overriding variables names, I'll keep the functionality as-is.

Situations like this are common when you source a generic dotenv file, then override with a user-specific dotenv file, or override with a variable of the same name using the local process environment.