Demo meaure_opts.rs fails to compile due to deny(warnings) with unused field 'debug' and 'paren_token'

[DavidAntliff]

Hi,

Not sure if there's more I needed to do, but, being new to this crate and wanting to see what the demo looks like, I tried:

$ git clone https://github.com/magnet/metered-rs.git magnet/metered-rs.git
$ cd magnet/metered-rs.git
$ git rev-parse HEAD
3f2d8dcf921758dc5ea285562efb25400876ad7f
$ cd demos
$ cargo run
   Compiling metered-macro v0.9.0 (/Users/david/git/github/magnet/metered-rs.git/metered-macro)
error: field `debug` is never read
  --> /Users/david/git/github/magnet/metered-rs.git/metered-macro/src/measure_opts.rs:16:9
   |
13 | pub struct MeasureRequest<'a> {
   |            -------------- field in this struct
...
16 |     pub debug: Option<&'a InvokePath>,
   |         ^^^^^
   |
note: the lint level is defined here
  --> /Users/david/git/github/magnet/metered-rs.git/metered-macro/src/lib.rs:5:9
   |
5  | #![deny(warnings)]
   |         ^^^^^^^^
   = note: `#[deny(dead_code)]` implied by `#[deny(warnings)]`

error: field `paren_token` is never read
  --> /Users/david/git/github/magnet/metered-rs.git/metered-macro/src/measure_opts.rs:56:9
   |
55 | pub struct NonEmptyMeasureRequestAttribute {
   |            ------------------------------- field in this struct
56 |     pub paren_token: syn::token::Paren,
   |         ^^^^^^^^^^^

error: could not compile `metered-macro` (lib) due to 2 previous errors

I'm using Rust stable 1.79.0.