Release Beta 4.2

4.2.0 Beta

Steps taken to release 4.2.0-beta on 2023-05-05.

• Check that my local working copy is on the master branch.
• git fetch upstream
• git rebase upstream/master
• git push to update my remote repository. My fork now matches the main one on github.com/0xfe/vexflow/
• npm ci
  • Oops a warning popped up.
  • Upgrade node to most recent stable version.
• npm ci again. Now it works!
• grunt clean
• grunt release:beta
  • While it's building... launch my 2FA app for logging into npm.
  • Question: "Publish vexflow@beta to npm?" Answer: Y