test(hydra-node): “get” asks hydra server when nocache  is true
refactor(hydra-node): check for valid cache copy
refactor(hydra-node): extracted side effect Date.now to timers lib

For better testing
test(hydra-node): “get” cache timeout
fixt(hydra-node): cycle hidra servers after “get” receives a bad request
style(hydra-node): clean unused variable and fix jshint issues
refactor(hydra-node): throw empty server list inside error object