Metadata checker

Adds an additional check to see if metadata can be retrieved for a particular sample.  Note that this touches python code, so the web server will have to be restarted after deployment.

Good barcodes you might use to test:
000001002 (should be all good)
000005739 (this is an animal sample, so metadata pulldown fails)
010001002 (this sample does not exist)
000001055 (this sample is missing sample data)