spawns with a different version of node on Travis

[kentcdodds]

I'm not sure what causes this, but I've reproduced the issue in this repo with this build

Here's the output:

Here's the code for that:

.travis.yml

language: node_js
cache:
  directories:
    - node_modules
node_js:
  - '6'
script:
  - npm run test

spawn.js

const defaultShell = require('spawn-default-shell')
const spawn = require('spawn-command')

go(defaultShell.spawn, 'spawn-default-shell').then(() => {
  go(spawn, 'spawn-command')
})

function go(spawnerFn, label) {
  console.log(`\n\n${label}\n`)
  const child = spawnerFn('./log-node-version.js')
  return new Promise(resolve => {
    child.stdout.on('data', (data) => {
      console.log(`${label}: stdout: ${data}`)
    })
    
    child.stderr.on('data', (data) => {
      console.log(`${label}: stderr: ${data}`)
    })
    
    child.on('close', (code) => {
      console.log(`${label}: child process exited with code ${code}`)
      resolve()
    })
  })
}

log-node-version.js

#!/usr/bin/env node

console.log('node version:', process.version)

You'll notice that spawn-command doesn't have the same problem. Is there anything that spawn-default-shell can do that spawn-command cannot? Perhaps concurrently could use spawn-command instead and spawn-default-shell can be deprecated?

Anyway, this is causing broken builds in my PR here which is why I bring it up. I'd really like to use concurrently! Let me know how I can help.

Thanks!