package.json: update dependencies
package.json: update dependencies

To get security fixes. `npm audit` doesn't find any vulnerabilities anymore,
except for some dependencies of browser-sync, which is not used in the
application itself.

weldr/welder-web,jkozol/welder-web,weldr/welder-web,jkozol/welder-web,jkozol/welder-web,jkozol/welder-web,weldr/welder-web,weldr/welder-web