Clean up after manifest-source removal

[wrygiel]

When manifest sources are removed, the data from its manifests is not removed from the manifest repository, but it seems that it should be.

[wrygiel]

This problem will probably "solve itself" once this feature is implemented: erasmus-without-paper/ewp-specs-api-discovery#7

[wrygiel]

This problem will probably "solve itself" once this feature is implemented: erasmus-without-paper/ewp-specs-api-discovery#7

This is only partially true. When a <host> element is removed from an otherwise valid <manifest>, then it will also be removed from the catalogue. However, if the whole manifest is removed, it still won't work.

[wrygiel]

Today we have removed lots of SOPs manifest files from DEV Registry's manifest-sources.xml file. Here's what happened:

• GOOD: All the removed manifests correctly disappeared from the catalogue.

• BAD: Old copies were NOT removed from the repository. You can see it here - I believe this folder should have been made empty in this commit, but it wasn't.

• BAD: The index.xml file also wasn't updated. I believe all SOP entries should have been removed in this commit, but weren't.

I won't have time to fix this issue before I leave the project, but hopefully these comments will help the future maintainers.