chapter-6/Listing 6.8 - Tests/test/test.js missing env variables

[Cuneytt]

Added two env variables to rewired.__set__

rewired.__set__({
      's3': {listObjects: listObjects},
      'process.env.BASE_URL': "https://s3.amazonaws.com",
      'process.env.BUCKET': "serverless-video-transcoded"
});

[sbarski]

Thank you @Cuneytt! Will add this to the next revision and to chapter6/test/test.js.