Bootstrap 4?

[spns]

Bootstrap 4 is in the works. I suppose we should test/upgrade the code for this.

[kaymes]

I don't think that's really necessary at this point.

• Bootstrap 4 is a complete rewrite, so there will be more than just a
  few changes.
• They say that they will continue to release important fixes for
  Bootstrap 3 even after 4 is released.
• Platypus hosts its own copies of all the frameworks, thus we are not
  dependent on any CDN being available and things should continue to work
  even after official support is dropped.

That said, it would probably be worthwhile to look at the bootstrap
package that we pull in via composer. If it is not specifically a
Bootstrap 3 package, it could happen, that the author updates the
package with 4 which means all hell breaks loose if you do a composer
update.
To prevent this, you can restrict the version of the package to be less
than 4. You should be able to specify this in the composer.json.