Closed Issue: Casablanca hangs my app when unloaded [309]

Hi,
Am trying to use Casablanca as a dll in another third party exe on Windows 7.

Everything works fine, except when closing the socket and unloading the dll.

My close function is as follows
```
void __stdcall WSDisconnect()
{
auto current_context = task_continuation_context::use_default();
create_task([=]()
{
try
{
m_ws_client.close().then([=](task<void> close_task) {
close_task.get();
});
}
catch (websocket_exception& wex)
{
}
}, current_context);
}
```

The close task closes and returns almost immediately, however the call to above function hangs till timeout ( enforced by the third party exe ).

Is this due to trying to use Casablanca on Windows 7 without WinRT, or something else. Any pointers on the fixing the issue welcome.

Regards

Vivek