Add permission for scripts only to run in Travis CI and not locally

I want to lock down some scripts in my .travis.yml to only be ran in the Travis CI build environment and prevent them from being ran locally on a users machine.

where the config in the .travis.yml would look something like this:

# .travis.yml

script:
  - npm run deploy-from-travis-only

If there is a better approach, I'm also open to other ideas.

from Add permission for scripts only to run in Travis CI and not locally