Cross compilation

Compilation and testing for other architectures is rather easy with cross.

1. Install cargo-cross.
2. Make sure to install qemu.

• On Arch-Linux install qemu-user-static-binfmt.
• On Ubuntu install binfmt-support and qemu-user-static.

Run the build/test against the target infrastructure, I.e.:

• cross build --target=aarch64-unknown-linux-musl
• cross test --target=aarch64-unknown-linux-musl