Different node versions per directory?

[drazisil]

This is actually pretty easy:

machine:
  node:
    version: 0.12
    
test:
  override:
    - test that you want to run with v0.12
    - nvm use 4.0; test you want to run with v4

Ref: https://circleci.com/gh/drazisil/fun-with-circle/4