Native proc_macro

[ta-vroom]

With Rust 1.45 #[proc_macro_hack] is no longer required as #[proc_macro] has a native implementation (it also results in an annoying unresolved-macro-call error.

Consider futures-macro's implementation for supporting older Rust compilers.

[voidpumpkin]

@ZoeyR Could you take a look at this?
It is very distracting to see the proc macro error in IDE

[hoijui]

This is fixed in the new repo:
https://github.com/allan2/dotenvy

[stevenhansel]

https://github.com/allan2/dotenvy

While this repo is not maintained anymore, I don't see that the problem is fixed yet in the fork

[hoijui]

To be honest... I tried to figure out why I wrote that here, and I guess I just posted in the wrong issue (meant to post in #63). So.. you are right, sorry!
(even #63 is only fixed in a reworked PR though, not merged)