Use AppVeyor's MSBuild custom logger and reduce verbosity level.

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Custom logger is required to push MSBuild warning and errors in real-time to build console.

Author: tritao

appveyor.yml

@@ -41,7 +41,7 @@ install:
 
 build_script:
   - build\premake5.exe --file=build\premake4.lua %VS_VERSION%
-  - msbuild %BUILD_PATH%\CppSharp.sln
+  - msbuild %BUILD_PATH%\CppSharp.sln /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll" /verbosity:minimal
 
 #---------------------------------#
 #      artifacts configuration    #