message: [cli] Add rust-toolchain file to generator
diff: @@ -158,6 +158,10 @@ wasm-opt -Oz target/$PROJNAME.wasm -o target/$PROJNAME-opt.wasm"##,
  )
  }
  +fn rust_toolchain_contents() -> String {
  + r##"nightly-2019-03-10"##.to_owned()
  +}
  +
  /// Initializes a project structure for the `lang` abstraction layer.
  fn initialize_for_lang(name: &str) -> Result<()> {
  use std::fs;
  @@ -184,7 +188,10 @@ fn initialize_for_lang(name: &str) -> Result<()> {
  filepath_from_segs(&[name, "build.sh"]),
  build_sh_contents(name),
  )?;
  -
  + fs::write(
  + filepath_from_segs(&[name, "rust-toolchain"]),
  + rust_toolchain_contents(),
  + )?;
  Ok(())
  }
  