language: node_js
before_install:
    - npm i -g npm

node_js:
    - 4
    - 6
    - 8
    - stable

language: node_js
before_install:
    - npm i -g npm

node_js:
    - 4
    - 6
    - 8

Remove `stable` from test suite
Remove `stable` from test suite

Currently broken with some `npm`-related issue.
