Update README.md
Optional API Key. Soften integration error when RIAK is not running.
Batch handling improvements. Switch to NonPersistent Neo4j for tests. Smooth tags loading profile. Merge on EventNode. Removed re-writing of tags attached to Header
Full merge of neo4j2.  Deadlock improvements, library upgrades.
Update README.md

Shortened the blurb
Tidy up of tests etc....
Tidy up of tests etc....
Version bump. Add support for locating MetaHeaders by a collection of MetaKeys
Library upgrades. Pubmed improvements