bug fix #454 #wip

[kathryn-ods]

removing 'securitiesListing' from the required properties on 'publicListing'

Overview

• What does this pull request do?
  make securitiesListing not required
• How can a reviewer test or examine your changes?
  eyeball
• Who is best placed to review it?
  kadie

(Closes/Relates to) issue: #454

Translations

n/a

Documentation & Release

• I've thought about how and when this needs to be released. See:
  https://openownership.github.io/bods-dev-handbook/standard_releases.html
• I've updated the changelog, if necessary.
  [n/a] I've updated reference.rst to reflect any changes to schema structure or naming.
  [n/a] I've added or edited any other related documentation. See: https://github.com/openownership/bods-dev-handbook/blob/master/style_guide.md

[kd-ods]

There is test which needs to be removed before checks clear on this PR: data/entity-statement/invalid/invalid-entity-statement-no-securitiesListings.json

[kd-ods]

@kathryn-ods - you can go ahead and update the changelog on this WIP branch now. There's guidance here about what to do, but basically you can add a new 'unreleased' heading then detail this little change under a 'Changed' subheading.

Have a go and I can review it from this PR. Ping me if you need to.

[kd-ods]

The changelog and everything looks good. This is ready to merge.