Run tests on AppVeyor

appveyor.yml

@@ -19,9 +19,16 @@ install:
 platform:
   - Win32
   - x64
-configuration: Release
+configuration:
+  - Release
+  - ReleaseTests
 build:
   project: openrct2.proj
+test_script:
+- ps: >-
+    if ($env:configuration -eq "ReleaseTests") {
+        msbuild openrct2.proj /t:test /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
+    }
 artifacts:
 - path: .\artifacts\openrct2-portable*.zip
   name: OpenRCT2-portable