Added NotifyPlugin unit tests and more

This patch restructures the unit tests for plugins.
This also adds unit tests for the NotifyPlugin

tests/plugins/test_version.py

@@ -0,0 +1,35 @@
+from unittest import mock
+
+import aprsd
+from aprsd.plugins import version as version_plugin
+
+from .. import fake, test_plugin
+
+
+class TestVersionPlugin(test_plugin.TestPlugin):
+    @mock.patch("aprsd.plugin.PluginManager.get_plugins")
+    def test_version(self, mock_get_plugins):
+        expected = f"APRSD ver:{aprsd.__version__} uptime:00:00:00"
+        version = version_plugin.VersionPlugin(self.config)
+
+        packet = fake.fake_packet(
+            message="No",
+            msg_number=1,
+        )
+
+        actual = version.filter(packet)
+        self.assertEqual(None, actual)
+
+        packet = fake.fake_packet(
+            message="version",
+            msg_number=1,
+        )
+        actual = version.filter(packet)
+        self.assertEqual(expected, actual)
+
+        packet = fake.fake_packet(
+            message="Version",
+            msg_number=1,
+        )
+        actual = version.filter(packet)
+        self.assertEqual(expected, actual)