Expose citation stats

#1

From @suenjedt on Thu Aug 09 2018 11:31:50 GMT+0000 (UTC)

As a information researcher, bibliometrician or …, I want to have all the citation stats from trusted sources, independent of a service provider (e.g. google scholar, …) with high quality metadata.

Copied from original issue: https://github.com/datacite/freya/issues/60