[Security] Bump nokogiri from 1.10.3 to 1.10.4 (#26)

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.10.3 to 1.10.4. **This update includes a security fix.**
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/master/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.10.3...v1.10.4)

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

Author: dependabot-preview[bot]

Gemfile.lock

@@ -64,11 +64,11 @@ GEM
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
     multi_json (1.13.1)
-    nokogiri (1.10.3)
+    nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
-    nokogiri (1.10.3-x64-mingw32)
+    nokogiri (1.10.4-x64-mingw32)
       mini_portile2 (~> 2.4.0)
-    nokogiri (1.10.3-x86-mingw32)
+    nokogiri (1.10.4-x86-mingw32)
       mini_portile2 (~> 2.4.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)