Merge pull request #504 from rubycentral/dependabot/bundler/chartkick-5.1.4

Bump chartkick from 5.1.3 to 5.1.4

Author: amatsuda

Gemfile.lock

@@ -154,7 +154,7 @@ GEM
       xpath (~> 3.2)
     case_transform (0.2)
       activesupport
-    chartkick (5.1.3)
+    chartkick (5.1.4)
     childprocess (5.1.0)
       logger (~> 1.5)
     coderay (1.1.3)