appveyor: add libs to build artifacts.

appveyor.yml

@@ -33,7 +33,7 @@ build_script:
  - msbuild /m /p:Configuration=Release /p:Platform="Win32" Assimp.sln
 
 after_build:
-  - 7z a assimp.7z c:\projects\assimp\bin\release\*
+  - 7z a assimp.7z c:\projects\assimp\bin\release\* c:\projects\assimp\lib\release\*
 
 artifacts:
   - path: assimp.7z