Bump nokogiri from 1.8.4 to 1.10.3 (#18)

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.8.4 to 1.10.3.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/master/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.8.4...v1.10.3)

Author: dependabot[bot]

Gemfile.lock

@@ -60,18 +60,18 @@ GEM
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
     mercenary (0.3.6)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     minima (2.5.0)
       jekyll (~> 3.5)
       jekyll-feed (~> 0.9)
       jekyll-seo-tag (~> 2.1)
     minitest (5.11.3)
-    nokogiri (1.8.4)
-      mini_portile2 (~> 2.3.0)
-    nokogiri (1.8.4-x64-mingw32)
-      mini_portile2 (~> 2.3.0)
-    nokogiri (1.8.4-x86-mingw32)
-      mini_portile2 (~> 2.3.0)
+    nokogiri (1.10.3)
+      mini_portile2 (~> 2.4.0)
+    nokogiri (1.10.3-x64-mingw32)
+      mini_portile2 (~> 2.4.0)
+    nokogiri (1.10.3-x86-mingw32)
+      mini_portile2 (~> 2.4.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (3.0.3)