Code and tests for handling Value responses.
Moved the distance function from the RoutingTable class in to the utils module.
Break out of sort_contacts in to drogulus.utils with associated tests and some false asserts for pending development in the NodeLookup class.
Added code and tests to ensure that nodes are sorted correctly in to the shortlist.
Final pieces of the NodeLookup class and related tests. Ensures the results are fired correctly for a Nodes response.