Support for Node LTS

[selvagsz]

Currently, razorNode is only supported on node >= 5.x which is quite troublesome for the users. Babelifying should help

[dezinezync]

I'll look into how this can be implemented without breaking the current structure. What's the minimum version you recommend supporting?

[selvagsz]

@dezinezync We find more users on 4.x versions & some even stumbling upon 0.12.x as well. We want to support >0.12.x versions

[dezinezync]

Thanks. That gives me a good point to start.