message: fix path to rustup
diff: @@ -8,10 +8,11 @@ RUN apt-get update && \
  # Install Rust toolchain
  RUN curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain nightly --profile minimal
  -RUN /root/.rustup/bin/rustup component add rust-src
  -RUN /root/.rustup/bin/rustup component add llvm-tools-preview
  RUN /root/.cargo/bin/cargo install cargo-download
  RUN /root/.cargo/bin/cargo install uhyve
  +RUN /root/.cargo/bin/rustup component add rust-src
  +RUN /root/.cargo/bin/rustup component add llvm-tools-preview
  +
  ENV PATH="/root/.cargo/bin:/root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/bin/:${PATH}"
  ENV EDITOR=vim
  