core/testdata: Add Justin O'Beirne feed.
core/testdata: Add Justin O'Beirne feed.

Note: This feed was actually directly imported via the Admin gRPC
service. This is a checked-in copy of the exported OPML thereafter.

jrupac/goliath,jrupac/goliath,jrupac/goliath,jrupac/goliath,jrupac/goliath