code: function getEnv (key, defaultValue) {
    let value = process.env[key]
    if (value === 'undefined') {
      value = undefined
    }
  
    return (value === undefined) ? defaultValue : value
  }
docs: Get the given key from process.env, substituting "undefined" for the real undefined
  @param {String} key - the environment variable we want to get
  @param {*} defaultValue - value to return if key not in env, or if it is 'undefined'
  @returns {*} whatever is at process.env[key] with the one exception of "undefined" being translated to undefined