Make PipeIOServer a contextmanager

pipe_io_server/pipe_io_server.py

@@ -77,3 +77,10 @@ class PipeIOServer(Thread):
 
     def wait(self):
         self._stop_event.wait()
+
+    def __enter__(self):
+        self.start()
+        return self
+
+    def __exit__(self, type_, value, tb):
+        self.stop()