Change format of dhcp_subnets to be a dict

Top level key is now subnet CIDR, rather than a list containing dicts,
where subnet is a sub-key, so better structured

- Update to pass more modern ansible-lint
- Fix galaxy info
- Format filter plugin w/black
- BSD fixes - paths, listening IP for tftpd server

Change-Id: I490331bc2998f2afbef135545500d1fa07b626ff
diff --git a/.reuse/dep5 b/.reuse/dep5
index 36ce305..40fef72 100644
--- a/.reuse/dep5
+++ b/.reuse/dep5
@@ -1,5 +1,5 @@
 Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
 
-Files: .cookiecutter_params.json VERSION .gitreview
+Files: .cookiecutter_params.json VERSION .gitreview README.md
 Copyright: 2020 Open Networking Foundation
 License: Apache-2.0