fix hasParent
fix hasParent

ddworken/pyethereum,inzem77/pyethereum,holiman/pyethereum,ebuchman/daoist_protocol,ebuchman/daoist_protocol,ethereum/pyethereum,karlfloersch/pyethereum,shahankhatch/pyethereum,vaporry/pyethereum,ethereum/pyethereum,shahankhatch/pyethereum,ethermarket/pyethereum,ckeenan/pyethereum,pipermerriam/pyethereum,harlantwood/pyethereum,pipermerriam/pyethereum,jnnk/pyethereum,ethers/pyethereum,karlfloersch/pyethereum