circle.yml in mutant-0.8.10 vs circle.yml in mutant-0.8.11

@@ -1,8 +1,8 @@
 ---
 machine:
   ruby:
-    version: '2.2'
+    version: '2.3.0'
 dependencies:
   pre:
     - bundle -v | grep -Fx "Bundler version 1.10.6" || gem install bundler --version 1.10.6
 test:
   override: