generator-travis - Get up-to-date travis config

You will get up-do-date travis config and will not loose existing config. Up to date config contains current node versions: stable (v4), 0.12 and 0.10. It’s easiest way to get up-to-date travis config in your project. And easiest way to stop worrying about travis config if you are maintaining your own custom generators, just compose generator-travis with them.