chore: add unittest for oneway req

tests/oneway.thrift

@@ -0,0 +1,4 @@
+service echo
+{
+    oneway void Test(1: string req)
+}

tests/test_oneway.py

@@ -0,0 +1,32 @@
+import multiprocessing
+import thriftpy2
+import time
+from thriftpy2.rpc import make_client, make_server
+
+
+class Dispatcher(object):
+    def Test(self, req):
+        print("Get req msg: %s" % req)
+
+        assert req == "Hello!"
+
+
+oneway_thrift = thriftpy2.load("oneway.thrift", module_name="oneway_thrift")
+multiprocessing.set_start_method("fork")
+
+
+class TestOneway(object):
+    def setup_class(self):
+        server = make_server(oneway_thrift.echo, Dispatcher(), '127.0.0.1', 6000)
+        self.p = multiprocessing.Process(target=server.serve)
+        self.p.start()
+        time.sleep(1)  # Wait a second for server to start.
+
+    def teardown_class(self):
+        self.p.terminate()
+
+    def test_echo(self):
+        req = "Hello!"
+        client = make_client(oneway_thrift.echo, '127.0.0.1', 6000)
+
+        assert client.Test(req) == None