Health and Rotation

Added functionality to check if a connector is healthy along with tests for it.  Added a fault_tolerance attribute to distributor to be decided by the consumer. Also added functionality to rotate the connectors round-robbin style.
Connector Distributor spec fix

Fixed bugs in the spec files for the Distributor and Connector.
Flipped logic fix

Fixed a bug with connector.healthy? with reversed logic.
Merge pull request #8 from mkb/prandium

Health and Rotation