Bump nokogiri from 1.10.4 to 1.10.9

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.10.4 to 1.10.9.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/v1.10.9/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.10.4...v1.10.9)

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

Author: dependabot[bot]

Gemfile.lock

@@ -19,7 +19,7 @@ GEM
       concurrent-ruby (~> 1.0)
     mini_portile2 (2.4.0)
     minitest (5.10.1)
-    nokogiri (1.10.4)
+    nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     rake (13.0.1)
     thread_safe (0.3.6)