test: remove support for EOL versions of Node.js
test: remove support for EOL versions of Node.js

Reviewed-By: Ben Noordhuis <59bd0a3ff43b32849b319e645d4798d8a5d1e889@bnoordhuis.nl>
Reviewed-By: Jiawen Geng <8f5a7089e1809fdab8e8d97ec73a77a8b0770d74@gmail.com>
Reviewed-By: Christian Clauss <585dd401264c1e46d17ebec1862e5d2a9b6a6c5d@me.com>
Reviewed-By: Rod Vagg <f9f03903429036ef609ed7ca822fddfa76155c29@vagg.org>

nodegit/node-gyp,nodegit/node-gyp,nodegit/node-gyp,nodejs/node-gyp,nodejs/node-gyp,nodejs/node-gyp,nodegit/node-gyp,nodejs/node-gyp,nodejs/node-gyp,nodegit/node-gyp