Feature/using six

[jamesbraza]

• Simplified script to use Python's compatibility library six. It eliminates the need to differentiate Python 2 and 3 when taking user input and parsing sys.argv.
  • Python 3 linters will no longer complain about unresolved references to raw_input or str.decode('utf-8')
    • Called six out as a required package in the README.md's pip installation instructions.
  • six is already a requirement of google-api-python-client (source), so it's not actually expanding required packages
    • Organized imports at top of transport.py by standard libraries vs 3rd party packages

[davidstrauss]

Nice work!

[jamesbraza]

Thanks!