Ensure syncing with HPO resources doesn't cause issues with our results

[bschilder]

Priority: high

Currently we pull info directly from the HPO API.

Ways in which this could cause problems:

• HPO IDs become deprecated
• HPO names change (not so much a problem, but could cause some confusion when comparing the names we have in our results)
• Gene lists could change

To mitigate this, is there a version-controlled URL for the API that uses a specific release of the HPO data? @missyQWQ