Updates to scripts after refactor

- Run black to reformat all the scripts
- Update makefile test targets, pylint, and fix some of the issues found
- Update pxeconfig script for refactored nbhelper
- Add start of inventory script

Change-Id: I5f426ac2da840dc72f07f8a6844e199e47d49135
diff --git a/playbooks/qa-playbook.yml b/playbooks/qa-playbook.yml
index d81b35f..d2fde4d 100644
--- a/playbooks/qa-playbook.yml
+++ b/playbooks/qa-playbook.yml
@@ -17,6 +17,7 @@
           - "ethtool"
           - "iperf"
           - "ipvsadm"
+          - "python-scapy"
           - "tcpdump"
           - "tcpreplay"
           - "traceroute"