Got faraday working with all e2e specs, issue #102

TODO
* fix unit tests
* clean up (e.g. puts)
* update docs
* test with basic auth
* make it possible to advanced configure faraday, proxy etc...
Fixed more unit specs for faraday, issue #102

We probably don't need to wrap the faraday response.
Fixed all specs for faraday, issue #102

Just need to review the commits now and maybe some cleanup
Removed the endpoint class and use faraday directly #102

Now only need to make faraday more configurable
Fix for using multiple sessions, closes #109

Neo4j::Session.open now always returns the session instead of the current session.
Make it possible for users to create their own faraday connection, closes #102
Improved coverage by removing unused code
Merge pull request #110 from neo4jrb/faraday2

Faraday2