Drop support for Node < 0.10

[silkentrance]

I strongly recommend dropping support for node < 0.10. The rationale here is that support by existing modern testing frameworks has also been dropped for these legacy versions. In addition, I do not really believe that any one is using these old versions any more except for testing.

See also https://semaphoreci.com/blog/2016/10/12/nodejs-versions-used-in-commercial-projects-2016-edition.html. While definitely not complete, as it does not encompass non commercial use, it should be something to take into account.

And here, while they do not take versions < 0.10 into account, it shows that even 0.10 is on decline
https://nodesource.com/node-by-numbers.

[silkentrance]

done with PR #141.