Merge pull request #483 from httpswift/dependabot/bundler/kramdown-2.3.1

Bump kramdown from 2.3.0 to 2.3.1

Gemfile.lock

@@ -34,7 +34,7 @@ GEM
       faraday (>= 0.8)
     git (1.7.0)
       rchardet (~> 1.8)
-    kramdown (2.3.0)
+    kramdown (2.3.1)
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)