language: node_js
node_js:
    - "6.1"
    - "5.2.0"
services: 
    - mongodb
cache:
  directories:
    - node_modules
language: node_js
node_js:
    - "node"
    - "7.7.1"
    - "6"
services: 
    - mongodb
cache:
  directories:
    - node_modules
Update the Node.js version Travis CI tests
Update the Node.js version Travis CI tests

We were having funky issues with version 5 of Node, which shouldn't be an issue in production, but was causing our tests to fail.
