Added ethereum-serpent as a dependency
Added ethereum-serpent as a dependency

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