[build-troubleshooting] ReveaNot sure

* Changing in response to:
  https://travis-ci.org/jedcn/reveal-ck/jobs/4664317

Which says:

/home/travis/build/jedcn/reveal-ck/rakelib/reveal.rake:6:in
`<top (required)>': uninitialized constant Object::CLOBBER (NameError)

/home/travis/build/jedcn/reveal-ck/bin/reveal-ck:10:in `load'
/home/travis/build/jedcn/reveal-ck/bin/reveal-ck:10:in `block in <main>'
/home/travis/build/jedcn/reveal-ck/bin/reveal-ck:9:in `each'
/home/travis/build/jedcn/reveal-ck/bin/reveal-ck:9:in `<main>'