Add support for Node.js 11/12

[pioug]

So far we updated:

• https://github.com/nfroidure/ttf2woff2/releases/tag/v3.0.0
• https://github.com/nfroidure/gulp-ttf2woff2/releases/tag/v3.0.0

We're almost done 😅

[pioug]

Thanks you @NaridaL for reviewing! Do you think we can release a (major) update for gulp-icon-font now?

Same with the other packages, I'll be happy to help with all the chores 🙌 (bump, triage issues/PR, small updates...)

[NaridaL]

@pioug Does this need a major version? Is there anything other than the fact that gulp-ttf2woff2 no longer supports node 0.12? The package.json here says "node": ">= 6.11.1" anyway.

[pioug]

Good point! We are dropping very old Node versions. I think we can bump a minor version since it doesn't affect the compatibility for this package 👍

[pioug]

Thank you @nfroidure for inviting me to the repository! I bumped and tagged a new version https://github.com/nfroidure/gulp-iconfont/releases/tag/v10.0.3. Next is publishing on npm and I think we're good with Node 12 💦

Thanks for following up on my PRs 🙌

[NaridaL]

👍 Yeah, sorry I was waiting on feedback to nfroidure/gulp-svgicons2svgfont#40, which would also need changes here, but this works too :-D

I can publish to npm this evening unless @nfroidure gives you access there too.

[nfroidure]

Jut added you @pioug thank you both for taking time to update all that legacy :)