`Alloc` trait removed in 1.43 nightlies

[rubdos]

We just tried building a test-application with 1.43.0-nightly, 2020-02-05, and it seems like core::alloc::Alloc got removed. Cfr. rust-lang/rust#32838 and the new core::alloc nightly documentation.

I am not experienced enough with custom allocators in Rust to fix this myself, and I don't really find what it was replaced with, so I'm just letting you know. Cc @Vanarill

[valff]

Thanks for the report. This will be fixed soon in the new Drone 0.12 release.