Standardize interpreter display format

[DonJayamanne]

Fixes #1351

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR)
• Title summarizes what is changing
• Has a news entry file (remember to thank yourself!)
• Has unit tests & system/integration tests
• [n/a] Any new/changed dependencies in package.json are pinned (e.g. "1.2.3", not "^1.2.3" for the specified version)
• [n/a] package-lock.json has been regenerated by running npm install (if dependencies have changed)

[DonJayamanne]

For some reason Travis CI isn't running. Close and reopen to check if that works.