Use new function macro

[konstin]

This is the new style that people should use.

CI won't pass until the 0.5 branch is merged.

[mre]

Super elegant. Thanks for that! 🎉

[mre]

Ehehe, we hit a compiler bug:

   Compiling failure v0.1.2
error: internal compiler error: librustc/traits/specialize/mod.rs:104: When translating substitutions for specialization, the expected specialization failed to hold
thread 'main' panicked at 'Box<Any>', librustc_errors/lib.rs:600:9
note: Run with `RUST_BACKTRACE=1` for a backtrace.
error: aborting due to previous error
note: the compiler unexpectedly panicked. this is a bug.
note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

Pretty sure reintegrating master does the trick, as pyo3 0.5 support has landed now.
Nevertheless, we should consider reporting this. My guess is, that's a known bug, though.

[konstin]

This compiler bug was the reason I had released 0.5 in the first place. I'm still not done with the breaking changes I wanted for that release (PyToken is done now, specialization still has some instances)

I've reported the bug at rust-lang/rust#55380.

[mre]

Sorry about the ensure_ascii. Just never got around to implementing the functionality behind it. 😅

[konstin]

It's required for the test suite, so I've just silenced the warning ¯\_(ツ)_/¯

[mre]

Thanks! 💰