Dovesnap

- immediately allocate OVS port at container Join (faster networking setup)
- upgrade faucet, gauge, pytype, docker, grafana, grpc

- reduce size of OVS and dovesnap containers (builders)
- upgrade to golang 1.16
- min TLS 1.3 version for faucetconfrpc
- pin more python dependencies (including graphviz, docker)

- upgrade faucet, grafana, pytype
- docker as a systemd service

- Use waitgroups to synchronize create/delete operations, including on exit.
- OVS 2.15.1
- Update faucet, gauge, pylint, grpc, grafana, docker, prometheus, faucetconfrpc

- dovesnap plugin no longer needs privileged: true
- update prometheus, grafana, pytype.

- restart/shutdown handling improvements, and network deletes now blocking to avoid leaked veths or other resources.
- Update pytype, docker, faucetconfrpc, prometheus, grafana, baseconv