message: Update beta instructions
  Tweaks w/ what I did today
diff: @@ -72,7 +72,7 @@ curl -sSf https://static.rust-lang.org/rustup.sh | sh -s -- --spec=stable-2015-0
  ## Promote master to beta (T-2 days, Tuesday)
  -Branch a cargo commit for the Rust beta:
  +Branch a rust-lang/cargo commit for the new beta:
  ```sh
  $ cd cargo
  @@ -80,17 +80,14 @@ $ git fetch rust-lang
  $ git push rust-lang rust-lang/master:rust-1.14.0
  ```
  -Promote master to beta as with yesterday:
  +Promote rust-lang/rust's master branch to beta as with yesterday:
  ```sh
  $ git fetch rust-lang
  $ git push rust-lang rust-lang/master:beta -f
  ```
  -Like yesterday, promote any nightly-only `*_cross_targets` arrays to also be
  -included on the beta channel.
  -
  -Send a commit to the freshly created beta branch of rust-lang/rust
  +Send a PR to the freshly created beta branch of rust-lang/rust
  which:
  - updates src/stage0.txt to bootstrap from this new stable
  @@ -101,11 +98,7 @@ which:
  build master. Do not update the Cargo version in this file.
  - Also update src/ci/run.sh to pass "--release-channel=beta".
  -Manually start the `beta-dist-rustc-trigger`. The beta build will use
  -the rustc binaries that already exist in the archives (only the
  -combined 'rust' package hasn't been uploaded). The beta will deploy
  -automatically.
  -
  +After this PR merges (through @bors) the beta should be automatically released.
  # Master bootstrap update (T-1 day, Wednesday)
  