Move build config to github actions

support/appveyor.yml

diff --git a/support/appveyor.yml b/support/appveyor.yml
index f53e438..64ca58a 100644
--- a/support/appveyor.yml
+++ b/support/appveyor.yml
@@ -6,11 +6,8 @@
 
 image:
   - Visual Studio 2015
-  - Visual Studio 2019
-  - Visual Studio 2017
 
 platform:
-  - Win32
   - x64
 
 environment:
@@ -18,13 +15,6 @@
   MSVC_DEFAULT_OPTIONS: ON
   BUILD: msvc
 
-matrix:
-  exclude:
-    - image: Visual Studio 2015
-      platform: Win32
-    - image: Visual Studio 2019
-      platform: Win32
-
 before_build:
  - mkdir build
  - cd build