language: node_js
node_js:
  - "4"
  - "6"
env:
  - CHAI_VERSION=^2.1.2
  - CHAI_VERSION=^3.0.0
  - CHAI_VERSION=^4.0.0
before_install:
    npm install -g grunt-cli
before_script:
    npm install chai@$CHAI_VERSION
script:
    grunt ci