VS2015 单元测试代码覆盖率
VS单元测试运行覆盖率检查，报错如下：
Empty results generated: No binaries were instrumented. Make sure the tests ran, required binaries were loaded, had matching symbol files, and were not excluded through custom settings. For more information see http://go.microsoft.com/fwlink/?LinkID=253731
切记选择“Managed Test Project”