Scheme-relative URL for DOI lookups (broken now)
Scheme-relative URL for DOI lookups (broken now)

This is in anticipation of ironing out our HTTPS problems with
CrossRef.org, see https://github.com/OpenTreeOfLife/opentree/issues/313

OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree,OpenTreeOfLife/opentree