appveyor.yml - add VS image, 2.6 [skip travis]

Author: MSP-Greg

appveyor.yml

@@ -22,7 +22,7 @@ test_script:
   - rake
 
 on_finish:
-  - ruby -v
+  - "echo Build Image %APPVEYOR_BUILD_WORKER_IMAGE% & ruby -v"
 
 deploy: off
 
@@ -35,6 +35,6 @@ environment:
     - ruby_version: 24-x64
     - ruby_version: 25
     - ruby_version: 25-x64
-    #- ruby_version: 26
-    #- ruby_version: 26-x64
+    - ruby_version: 26
+    - ruby_version: 26-x64
     - ruby_version: _trunk