Add note about version pinning functionality change

[pwillis-els]

This change notes the need to pass --latest=false to use pinned versions as a user might expect

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your master branch!
  (I don't know what this means?)
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
  (linked in the body of the text)
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

[timja]

not great, but sure we can include this.