Use new travis-ci infrastructure
Use new travis-ci infrastructure

Currently travis builds are killed preliminary. According to
http://docs.travis-ci.com/user/migrating-from-legacy/
adding `sudo: false` should move the builds to the new infrastructure.
Hopefully this helps...

ethereum/pyethereum,inzem77/pyethereum,ckeenan/pyethereum,karlfloersch/pyethereum,ethereum/pyethereum,vaporry/pyethereum,karlfloersch/pyethereum,pipermerriam/pyethereum,shahankhatch/pyethereum,pipermerriam/pyethereum,shahankhatch/pyethereum,holiman/pyethereum,harlantwood/pyethereum