changed types in hashing
changed types in hashing

addresses issue #31

imanolarrieta/RL,BerkeleyAutomation/rlpy,rlpy/rlpy,silgon/rlpy,rlpy/rlpy,imanolarrieta/RL,rlpy/rlpy,MDPvis/rlpy,BerkeleyAutomation/rlpy,BerkeleyAutomation/rlpy,imanolarrieta/RL,MDPvis/rlpy,MDPvis/rlpy,silgon/rlpy,silgon/rlpy