Investigate better ways to get a raw socket for chewie

[gizmoguy]

Currently when 8021x is in use (via chewie helper) we need to run faucet as root to bind to a raw NFV socket.

Some potential fixes:

• Investigate a framework for running separate NFV helper applications along side faucet
• Use linux capabilities to grant chewie CAP_NET_RAW

[gizmoguy]

This also impacts the ability to run our faucet unit tests as a non-root user.

Looks like the chewie unit tests when run as standard user will emit errors that they couldn't get a raw socket.