Implement (newer) Metadata API

[thekaveman]

See https://socratametadataapi.docs.apiary.io

• Fix the URL for metadata API calls
• Support optional page and limit parameters for GET requests
• Use the PATCH verb for updates to metadata
• Update the ResourceMetadata object model accordingly

[lmeyers]

The metadata api calls are no longer working for me....curious if there has been any progress on this issue?