ci(appveyor): remove node 6, add node 12
diff --git a/.appveyor.yml b/.appveyor.yml
index 1fc0937..015e7ba 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -15,9 +15,9 @@
   PLATFORM: windows-10-store
   JUST_BUILD: --justBuild
   matrix:
-    - nodejs_version: "6"
     - nodejs_version: "8"
     - nodejs_version: "10"
+    - nodejs_version: "12"
 
 platform:
   - x86