Pin toolchain to specific nightly version (#66)
Pin toolchain to specific nightly version (#66)

* Use new toolchain TOML format

This allows us to specify a specific version and needed components that rustup can then automatically install.

* Toolchain: Bump Version to 2020-11-25

- All required components available
- Tested to build using rustup preview 1.23.0 (61085d236)
hermitcore/rusty-hermit,hermitcore/rusty-hermit