introduce `make check-modules`, dependency of `bundles`
introduce `make check-modules`, dependency of `bundles`

As suggested by Wichert (#255) this ensures that tests on modules pass
before building bundles. `make check` additionally runs the tests
against the bundles.

The website now runs `make bootstrap bundles` to also account for
changed npm dependencies as early happened today.

garbas/Patterns,garbas/Patterns,janga1997/Patterns,garbas/Patterns,janga1997/Patterns,janga1997/Patterns