appveyor.yml in knife-windows-1.6.0 vs appveyor.yml in knife-windows-1.7.0

@@ -9,13 +9,13 @@
 
   matrix:
     - ruby_version: "20"
       chef_version: "< 12"
 
-    - ruby_version: "21"
+    - ruby_version: "23"
       chef_version: "~> 12.0"
 
-    - ruby_version: "21"
+    - ruby_version: "23"
       chef_version: "master"
 
 clone_folder: c:\projects\knife-windows
 clone_depth: 1
 branches: