Dynafed-storagestats

CHANGE: Updated docstrings on all modules (except 'exceptions') to conform with
PEP257.

ADDED: For S3, added cloudwatch() function to obtain the following metrics:
BucketSizeBytes and NumberOfObjects. These need to be setup in AWS
before being able to poll.

CHANGE: Argparse has been moved from runner.py to args.py. Now it works as
different functions for each of the sub-commands.
CHANGE: main() in runner.py has been split. Now it selects which sub-command
function to run depending on the positional argument passed by the
user. Added stats() and reports() functions.

FIX: Azure list-blob can get full list of blobs on containers with > 5k blobs.

CHANGE: Installable package.
CHANGE: Added sub-commands to dyanfed-storage executable instead of
dyanfed_storagestats.
CHANGE: -c flag now accepts several arguments for file paths instead of
having to use it several times. -d flag has been removed.
CHANGE: -o specifies output directory for flags -j, -x and -p.
CHANGE: Arguments for -j, -x, and -p change the default filename.

and suggestions from pylint.