appveyor: use MSVS 2013

kevinmehall · kevinmehall · commit 4fbd8dea6e50 · 2015-02-26T15:14:35.000-08:00
diff --git a/appveyor.yml b/appveyor.yml
@@ -1,3 +1,6 @@
+environment:
+  GYP_MSVS_VERSION: 2013
+
 install:
   - ps: Install-Product node 0.10 $env:platform
   - npm install -g node-gyp
