Transpile to desired Node version

Add option to setup babel transpile to current node version?

Using https://github.com/babel/babel-preset-env maybe target something like Node 4 by default

```
{
targets: {
node: "4"
}
}
```

Start by locating the generator's Babel setup and package configuration, since the issue does not name specific files or tests. Check how Babel options are currently assembled, then verify that the generator can target the current Node version while retaining Node 4 as the default.

Written by the indexing model from the issue text.