Update dependencies to support Node 14

[NicolasReibnitz]

Installing the package on Node v14.16.0 wasn't possible, because of node-sass and using the C++ binaries in ttf2woff2 failed (but fell back to use their Emscripten approach).

• [email protected] was locked to use [email protected]. Re-installing it allowed to use [email protected] which supports Node 14.

• sunflowerdeath/webfonts-generator is archived and outdated. vusion/webfonts-generator seems to have picked up the torch and updated their dependencies just 2 months ago ([email protected]). Also supporting Node 14. Unfortunately, they did not update their NPM package. So I used their repo as dependency.

Finally, running npm audit fix got rid of all 17 security issues without breaking changes.

Installing the package and running grunt works flawlessly now. And compiling the WOFF font is a lot faster using the binaries.