Bump nokogiri from 1.8.5 to 1.10.8

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.8.5 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@v1.8.5...v1.10.8)

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

Author: dependabot[bot]

Gemfile.lock

@@ -38,12 +38,12 @@ GEM
     jwt (2.1.0)
     method_source (0.9.2)
     mime-types (2.99.3)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     multi_json (1.13.1)
     multi_xml (0.6.0)
     multipart-post (2.0.0)
-    nokogiri (1.8.5)
-      mini_portile2 (~> 2.3.0)
+    nokogiri (1.10.8)
+      mini_portile2 (~> 2.4.0)
     oauth2 (1.4.1)
       faraday (>= 0.8, < 0.16.0)
       jwt (>= 1.0, < 3.0)