Temporarly disable VC 2013 appveyor build in order to test VC 2015
diff --git a/appveyor.yml b/appveyor.yml
index 13be7fa..e35a460 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -12,7 +12,7 @@
 
 environment:
   matrix:
-    - compiler: msvc-12-seh
+#    - compiler: msvc-12-seh
     - compiler: msvc-14-seh
     - compiler: gcc-4.9.2-posix
 #    - compiler: gcc-4.8.4-posix