Check examples for validitty

[pnrobinson]

While developing https://github.com/phenopackets/phenopacket-validator, I am noticing that several of the examples in this repository are not valid. For instance, the AML example shows this error

$.metaData.resources[0].iriPrefix: is missing but it is required

This issue is so we do not forget to check all examples once the validator software is finished.

[pnrobinson]

For the COVID example:

$.id: is missing but it is required
$.metaData.created: is missing but it is required
$.metaData.createdBy: is missing but it is required
$.metaData.resources[0].iriPrefix: is missing but it is required
$.metaData.resources[1].version: is missing but it is required
$.metaData.resources[1].iriPrefix: is missing but it is required
$.metaData.resources[2].version: is missing but it is required
$.metaData.resources[2].iriPrefix: is missing but it is required
$.metaData.resources[3].version: is missing but it is required
$.metaData.resources[3].iriPrefix: is missing but it is required