Update to Rust nightly
Update to Rust nightly

antoinealb/rust-demo-cortex-m4,SillyFreak/rust-demo-cortex-m4,nuft/rust-demo-cortex-m4,nuft/rust-demo-cortex-m4,antoinealb/rust-demo-cortex-m4,SillyFreak/rust-demo-cortex-m4