Bump snabbdom from 0.7.4 to 3.5.1

Bumps [snabbdom](https://github.com/snabbdom/snabbdom) from 0.7.4 to 3.5.1.
- [Release notes](https://github.com/snabbdom/snabbdom/releases)
- [Changelog](https://github.com/snabbdom/snabbdom/blob/master/CHANGELOG.md)
- [Commits](snabbdom/snabbdom@v0.7.4...v3.5.1)

---
updated-dependencies:
- dependency-name: snabbdom
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -60,7 +60,7 @@
     "promise-polyfill": "^8.2.0",
     "rbush": "^3.0.1",
     "requirejs": "^2.3.6",
-    "snabbdom": "^0.7.4"
+    "snabbdom": "^3.5.1"
   },
   "scripts": {
     "gulp": "./node_modules/gulp-cli/bin/gulp.js",