Correct old examples/ reference - use testprojects/ copy.

Testing Done:
CI went green here: https://travis-ci.org/pantsbuild/pants/builds/35687312

Bugs closed: 585

Reviewed at https://rbcommons.com/s/twitter/r/1049/
Merge branch 'master' of https://github.com/pantsbuild/pants into jsirois/ci/no-containers