ncei-trajectory:2.0 low priority suggested global attribute checks

[MathewBiddle]

I am running a file against the ncei-trajectory:2.0 template and I think there is something wonky going on with the data_metdata_modified low priority check. The contents of the attribute date_metadata_modified are in ISO-8601 format (eg. "2021-04-20"). From the looks of the message, the check is looking for an ISO duration, not date, which I don't think is correct. Below is the message from the checker:

date_metadata_modified should exist and be ISO-8601 format (example: PT1M30S), currently: 2021-04-20

Also, it looks like the contributor_name and contributor_role checks are duplicated:

• contributor_name should exist and not be empty.
• contributor_role should exist and not be empty.
• contributor_name should exist and not be empty.
• contributor_role should exist and not be empty.