fix doc string __key to _key
agents init with predecessors = [], empty list
commented out un-testable function path for random.random()
random.random() range is a semi-open range [0.0, 1.0)
it makes no sense to test anything else other than <.5 and >=.5
as this covers all the possible ranges of what can be returned
test hashing function
test predecessors
test 'random' functions by setting seed (base agent and binaryAgent)