Bump nokogiri from 1.10.2 to 1.10.4

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.10.2 to 1.10.4.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/master/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.10.2...v1.10.4)

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -11,7 +11,7 @@ GEM
       rack
       socksify
     mini_portile2 (2.4.0)
-    nokogiri (1.10.2)
+    nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
     nori (2.6.0)
     rack (2.0.6)