NodeJs 0.10 & 0.12 LTS support

[DanPurdy]

Node Js 0.10 is about to drop out of maintenance at the end of October with 0.12 set to follow at the end of December.

https://github.com/nodejs/LTS

My plan has always been to drop 'support' for these legacy versions once they dropped out of maintenance. With the usage stats of 0.12 being so low I think it's not a push to drop support for it when we drop 0.10 at the end of this month.

This doesn't mean we're going to intentionally break things it just means that we will be removing 0.10 and 0.12 from our test matrices. Any ongoing work in Sass-lint therefore won't necessarily work on these versions of Node. Unless we meet any significant resistance or requests to not do this I think we can expect to see the next release or two to drop this support.

Previous versions will obviously continue to work as before.