Further appveyor fix for x64 environ

Author: quicknir

appveyor.yml

@@ -11,7 +11,8 @@ environment:
       CONFIG: Release
 
 build_script:
-  - vcpkg install catch2
+  - vcpkg install catch2:x86-windows
+  - vcpkg install catch2:x64-windows
   - ps: cd test
   - cmake -DCMAKE_TOOLCHAIN_FILE=c:/tools/vcpkg/scripts/buildsystems/vcpkg.cmake "-G%GENERATOR%" -H. -B_builds -DENABLE_TESTING=1
   - cmake --build _builds --config "%CONFIG%"