removing ruby 2.2 from appveyor

Author: João M. D. Moura

appveyor.yml

@@ -10,8 +10,6 @@ environment:
     - ruby_version: "200-x64"
     - ruby_version: "21"
     - ruby_version: "21-x64"
-    - ruby_version: "22"
-    - ruby_version: "22-x64"
 
 install:
   - SET PATH=C:\Ruby%ruby_version%\bin;%PATH%