update to include 2.0.0-RC3 change

/* for 2.0.0-RC3, use: console.log(node._id) */

node.id is undefined in 2.0.0-RC3
Merge pull request #34 from philippkueng/develop

Merging Develop into Master
Merge pull request #32 from lazaruslarue/patch-1

update README.md, 2.0.0-RC3 insertNode callback arguments are diff
updated README to include all cases of where .id changed with 2.0.0-RC3
bumped version to 2.0.0-RC4
adding readTypedRelationshipsOfNode(node, types)
Merge pull request #37 from wfreeman/master

adding readTypedRelationshipsOfNode(node, types)
Merge branch 'refs/heads/master' into develop

Conflicts:
	README.md
	main.js
	package.json
	test/test.main.js