Re-added matrix specifier

Simon Hofmann · Simon Hofmann · commit 841ac3b22cee · 2019-09-25T16:20:12.000+02:00
diff --git a/appveyor.yml b/appveyor.yml
@@ -3,9 +3,10 @@
 image: Visual Studio 2017
 
 environment:
-  nodejs_version: 10
-  nodejs_version: 11
-  nodejs_version: 12
+  matrix:
+    nodejs_version: 10
+    nodejs_version: 11
+    nodejs_version: 12
 
 cache:
   - node_modules
