old_contents: import pyspark
  conf = pyspark.SparkConf()
  
  conf.setMaster("spark://192.168.99.100:7077")
  conf.setAppName('test')
  
  sc = pyspark.SparkContext(conf=conf)
  
  rdd = sc.parallelize(range(100))
new_contents: import pyspark
  conf = pyspark.SparkConf()
  
  conf.setMaster("spark://<docker machine IP>:7077")
  conf.setAppName('test')
  
  sc = pyspark.SparkContext(conf=conf)
  
  rdd = sc.parallelize(range(100))
  print(rdd.reduce(lambda x,y: x+y))
subject: Make the test application actually print something...