Test new Node version

I also removed a node version that is no longer supported

Author: Almenon

appveyor.yml

@@ -11,14 +11,14 @@ image:
 environment:
   matrix:
 
-    - nodejs_version: "12"
-      PYTHON: "C:\\Python37-x64"
-
     - nodejs_version: "14"
       PYTHON: "C:\\Python37-x64"
 
     - nodejs_version: "16"
       PYTHON: "C:\\Python37-x64"
+      
+    - nodejs_version: "18"
+      PYTHON: "C:\\Python37-x64"
 
 install:
   - cmd: powershell Install-Product node $env:nodejs_version