ALM-657 show metrics on single decorator
ALM-657 reverted back to previous version of retrieval_status decorator
ALM-657 added sensible defaults for number of workers and rate-limits
ALM-657 use crossref for signposts that are not PLOS
ALM-640 link from visualizations to sources in admin panel
ALM-640 added description to v5 sources API
ALM-657 send monthly report alert email as bcc
ALM-655 silently exit pmc rake task if source is not active
ALM-655 updated documentation: how to install design_docs for report
ALM-655 temporarily disable mysql for travis