client: add certificate parameters

tests/test_client.py

@@ -67,3 +67,19 @@ def test_set_self_deaf_noop_when_disconnected():
     client = MumbleClient(host="localhost")
     # Should not raise when not connected
     client.set_self_deaf(True)
+
+
+def test_cert_defaults():
+    client = MumbleClient(host="localhost")
+    assert client._certfile == ""
+    assert client._keyfile == ""
+
+
+def test_cert_custom():
+    client = MumbleClient(
+        host="localhost",
+        certfile="/path/cert.pem",
+        keyfile="/path/key.pem",
+    )
+    assert client._certfile == "/path/cert.pem"
+    assert client._keyfile == "/path/key.pem"