Define TestSocketInet class

doing helper_startup.fixSocket() in setUpClass - to be inherited by
any test case using protocol.encodeHost().

src/tests/test_packets.py

@@ -1,14 +1,15 @@
+"""Test packets creation and parsing"""
 
-import unittest
 from binascii import unhexlify
 from struct import pack
 
 from pybitmessage import addresses, protocol
 
 from .samples import magic
+from .test_protocol import TestSocketInet
 
 
-class TestSerialize(unittest.TestCase):
+class TestSerialize(TestSocketInet):
     """Test serializing and deserializing packet data"""
 
     def test_varint(self):

src/tests/test_protocol.py

@@ -9,14 +9,18 @@ from pybitmessage import protocol, state
 from pybitmessage.helper_startup import fixSocket
 
 
-class TestProtocol(unittest.TestCase):
-    """Main protocol test case"""
+class TestSocketInet(unittest.TestCase):
+    """Base class for test cases using protocol.encodeHost()"""
 
     @classmethod
     def setUpClass(cls):
         """Execute fixSocket() before start. Only for Windows?"""
         fixSocket()
 
+
+class TestProtocol(TestSocketInet):
+    """Main protocol test case"""
+
     def test_checkIPv4Address(self):
         """Check the results of protocol.checkIPv4Address()"""
         token = 'HELLO'