Bump nokogiri from 1.8.1 to 1.10.8

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.8.1 to 1.10.8.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/master/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.8.1...v1.10.8)

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

Gemfile.lock

@@ -50,10 +50,10 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
     mercenary (0.3.6)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     multipart-post (2.0.0)
-    nokogiri (1.8.1)
-      mini_portile2 (~> 2.3.0)
+    nokogiri (1.10.8)
+      mini_portile2 (~> 2.4.0)
     pathutil (0.16.1)
       forwardable-extended (~> 2.6)
     public_suffix (3.0.1)