First version to fetch, uncompress and dump DCU blobs.

By default, it's the raw format (txt) dump from DCU. You
can also dump JSON format.

Usage: dcu-fetch.py [options] dcu feed blob fetcher

Options:
  -h, --help            show this help message and exit
  -d, --debug           output debug message on stderr
  -a ACCOUNT_NAME, --account_name=ACCOUNT_NAME
                        Microsoft Azure account name
  -k ACCOUNT_KEY, --account_key=ACCOUNT_KEY
                        Microsoft Azure key to access DCU container
  -c, --clear           Delete blobs and containers after fetching
  -e, --header          Remove field header in the output (default is
                        displayed)
  -f OUTPUT_FORMAT, --format=OUTPUT_FORMAT
                        output txt, json (default is txt)