Sonobuoy v0.18.3

What's better

The Sonobuoy Results format now uses map[string]interface{} as the type for the details field. This allows arbitrary data to be included in this field. For compatibility with other results processing operations, only string keys should be used in any maps contained within this field.
The delete --all command will now identify namespaces for deletion by checking for the presence of the e2e-framework and e2e-run labels instead of the e2e- name prefix.
The default value for e2e plugin environment variable E2E_PARALLEL has been changed to "false" as the upstream script that consumes the value expects it to be boolean.

3e8a10e Prepare v0.18.3 release (#1131)
03ae14e Allow arbitrary data in Details map in results (#1130)
c4956c0 Improve E2E namespace cleanup (#1126)
385f41e Change default value for E2E_PARALLEL (#1124)
e1a28d2 README.md: Fix broken link to docker (#1121)
f862e4b Add blog post for who-can plugin (#1120)