Clap: Use of deprecated "std::sync::ONCE_INIT"

[Zooce]

Rust Version

rustc 1.38.0 (625451e37 2019-09-23)

Affected Version of clap

clap v2.33.0

Bug or Feature Request Summary

Warnings for use of deprecated feature.

Expected Behavior Summary

No warnings for use of deprecated feature.

Actual Behavior Summary

warning: use of deprecated item 'std::sync::ONCE_INIT': the `new` function is now preferred
   --> src\settings.rs:151:17
    |
151 |         .author(clap::crate_authors!("\n"))
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(deprecated)]` on by default
    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

warning: use of deprecated item 'std::sync::ONCE_INIT': the `new` function is now preferred
   --> src\settings.rs:151:17
    |
151 |         .author(clap::crate_authors!("\n"))
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: this warning originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

Steps to Reproduce the issue

Build an app that uses clap::crate_authors!("\n") with the versions of rustc and clap provided above.

[Zooce]

Similar to #1517

[bwinton]

I'm seeing this warning a bunch, and I'm glad that it's fixed, but am wondering if I could ask you to do a release that includes it to calm my compiler down? 😉

(But if a 3.0 beta release is upcoming, I'll happily switch to that instead! 🙂)