tests(appveyor): drop < node v4 & add v13

Author: Salakar

appveyor.yml

@@ -3,12 +3,11 @@
 # Test against these versions of Node.js.
 environment:
   matrix:
-    - nodejs_version: "0.10"
-    - nodejs_version: "0.12"
     - nodejs_version: "4"
     - nodejs_version: "6"
     - nodejs_version: "8"
     - nodejs_version: "12"
+    - nodejs_version: "13"
 
 pull_requests:
   do_not_increment_build_number: true