spec changes required for 2.2
Merge pull request #626 from neo4jrb/2.2updates

spec changes required for 2.2
require neo4j-core in rakefile
two simple activerel specs to demonstrate automatic typing
Merge branch 'master' of github.com:neo4jrb/neo4j
bump version 4.0.0.rc.1, use neo4j-core 3.1.0