update testing versions

node8 and python 2 is no longer supported as of 2020

Author: Almenon

appveyor.yml

@@ -10,17 +10,11 @@ image:
 
 environment:
   matrix:
-    - nodejs_version: "8"
-      PYTHON: "C:\\Python27"
-    
-    - nodejs_version: "8"
-      PYTHON: "C:\\Python36-x64"
-    
-    - nodejs_version: "10"
-      PYTHON: "C:\\Python27"
-    
     - nodejs_version: "10"
       PYTHON: "C:\\Python36-x64"
+
+    - nodejs_version: "12"
+      PYTHON: "C:\\Python36-x64"
 
 install:
   - cmd: powershell Install-Product node $env:nodejs_version