"unexpected keyword argument" after loadImagesAsSeries on s3

[industrial-sloth]

Running on an ec2 cluster launched via the thunder-ec2 script...

series = tsc.loadImagesAsSeries("s3n://thunder.datasets/test/tif-stack-2/", inputformat='tif-stack')
series.first()

some output happens, then:

 org.apache.spark.api.python.PythonException: Traceback (most recent call last):
  File "/root/spark/python/pyspark/worker.py", line 79, in main
    serializer.dump_stream(func(split_index, iterator), outfile)
  File "/root/spark/python/pyspark/serializers.py", line 196, in dump_stream
    self.serializer.dump_stream(self._batched(iterator), stream)
  File "/root/spark/python/pyspark/serializers.py", line 127, in dump_stream
    for obj in iterator:
  File "/root/spark/python/pyspark/serializers.py", line 185, in _batched
    for item in iterator:
  File "/root/spark/python/pyspark/rdd.py", line 1148, in takeUpToNumLeft
    yield next(iterator)
  File "thunder/rdds/fileio/seriesloader.py", line 362, in readblockfromtif
  File "build/bdist.linux-x86_64/egg/thunder/rdds/fileio/readers.py", line 448, in close
    self._key.close(fast=True)
TypeError: close() got an unexpected keyword argument 'fast'

[industrial-sloth]

This is a boto versioning problem - the ec2 cluster is provisioned (apparently) with boto 2.8.0, where it appears the "fast" keyword in close() doesn't exist yet. I'll get rid of that keyword and anything else that crept in requiring newer versions of boto.