Update CI build to VS 2019

Numpsy · Numpsy · commit aae2678e8fe6 · 2021-02-13T15:54:43.000Z
diff --git a/appveyor.yml b/appveyor.yml
@@ -1,6 +1,6 @@
 version: '{build}'
 skip_tags: true
-image: Visual Studio 2017
+image: Visual Studio 2019
 configuration: Release
 build_script:
 - ps: ./Build.ps1
