fix unit test with old versions of boost

gcontini

2020-02-10 205c71575c272a685011c641a33d26cf66cf60a0

 src/library/os/execution_environment.hpp

@@ -25,13 +25,15 @@
   ALI_CLOUD
} CLOUD_PROVIDER;

typedef enum { BARE_TO_METAL, VMWARE, VIRTUALBOX, XEN, KVM } VIRTUALIZATION_DETAIL;

class ExecutionEnvironment {
public:
   ExecutionEnvironment(){};
   virtual ~ExecutionEnvironment(){};
   VIRTUALIZATION getVirtualization();
   bool is_cloud();
   bool is_docker();
   CLOUD_PROVIDER getCloudProvider();
};

}  // namespace license