Refactor interop tests and factories

- Add `close` and `disconnect` in `Host`
- Add `close` and `close_peer` in `Network`
- Change `IListener.close` to async, to await for server's closing
- Add factories for security transports, and modify `HostFactory`

libp2p/transport/listener_interface.py

@@ -21,9 +21,8 @@ class IListener(ABC):
         """
 
     @abstractmethod
-    def close(self) -> bool:
+    async def close(self) -> None:
         """
         close the listener such that no more connections
         can be open on this transport instance
-        :return: return True if successful
         """

libp2p/transport/tcp/tcp.py

@@ -45,20 +45,16 @@ class TCPListener(IListener):
         # TODO check if server is listening
         return self.multiaddrs
 
-    def close(self) -> bool:
+    async def close(self) -> None:
         """
         close the listener such that no more connections
         can be open on this transport instance
-        :return: return True if successful
         """
         if self.server is None:
-            return False
+            return
         self.server.close()
-        _loop = asyncio.get_event_loop()
-        _loop.run_until_complete(self.server.wait_closed())
-        _loop.close()
+        await self.server.wait_closed()
         self.server = None
-        return True
 
 
 class TCP(ITransport):