Bump nokogiri from 1.10.1 to 1.10.4 (#125)

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.10.1 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@v1.10.1...v1.10.4)

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

Author: dependabot[bot]

Gemfile.lock

@@ -198,7 +198,7 @@ GEM
     net-ssh (4.2.0)
     net-telnet (0.1.1)
     netrc (0.11.0)
-    nokogiri (1.10.1)
+    nokogiri (1.10.4)
       mini_portile2 (~> 2.4.0)
     oga (2.15)
       ast