Bump nokogiri from 1.8.4 to 1.10.8

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.8.4 to 1.10.8.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sparklemotion/nokogiri/compare/v1.8.4...v1.10.8)

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

Gemfile.lock

@@ -25,9 +25,9 @@ GEM
     http-form_data (2.1.1)
     http_parser.rb (0.6.0)
     httpclient (2.6.0.1)
-    mini_portile2 (2.3.0)
-    nokogiri (1.8.4)
-      mini_portile2 (~> 2.3.0)
+    mini_portile2 (2.4.0)
+    nokogiri (1.10.8)
+      mini_portile2 (~> 2.4.0)
     public_suffix (3.0.2)
     sqlite3 (1.3.10)
     sqlite_magic (0.0.3)