python3 s3 flask which works with only simple config changes

[keiranmraine]

This is a very quick to demonstrate template for python3:

• Tested against a CEPH gateway.
• All values and config for both UI and server in 3 simple files.
• Documents possible issues
• Detailed description of how to get it running.

[rnicholus]

Thanks for the work! Sorry it took me so long.