Feature(escpos) Add buzzer function (#535)

* Add buzzer function
* Add `buzzer(time, duration)` function to control the buzzer on supported
   printers.
* Add unit tests for buzzer function.
* Update test_function_buzzer.py to pass black
* Run black in tests files
---------

Co-authored-by: Patrick Kanzler <dev@pkanzler.de>

test/test_function_buzzer.py

@@ -0,0 +1,54 @@
+import six
+import pytest
+
+from escpos import printer
+from escpos.constants import BUZZER
+
+
+def test_buzzer_function_with_default_params():
+    instance = printer.Dummy()
+    instance.buzzer()
+    expected = BUZZER + six.int2byte(2) + six.int2byte(4)
+    assert instance.output == expected
+
+
+@pytest.mark.parametrize(
+    "times, duration",
+    [
+        [1, 1],
+        [2, 2],
+        [3, 3],
+        [4, 4],
+        [5, 5],
+        [6, 6],
+        [7, 7],
+        [8, 8],
+        [9, 9],
+    ],
+)
+def test_buzzer_function(times, duration):
+    instance = printer.Dummy()
+    instance.buzzer(times, duration)
+    expected = BUZZER + six.int2byte(times) + six.int2byte(duration)
+    assert instance.output == expected
+
+
+@pytest.mark.parametrize(
+    "times, duration, expected_message",
+    [
+        [0, 0, "times must be between 1 and 9"],
+        [-1, 0, "times must be between 1 and 9"],
+        [10, 0, "times must be between 1 and 9"],
+        [11, 0, "times must be between 1 and 9"],
+        [3, 0, "duration must be between 1 and 9"],
+        [3, -1, "duration must be between 1 and 9"],
+        [3, 10, "duration must be between 1 and 9"],
+        [3, 11, "duration must be between 1 and 9"],
+    ],
+)
+def test_buzzer_fuction_with_outrange_values(times, duration, expected_message):
+    instance = printer.Dummy()
+    with pytest.raises(ValueError) as e:
+        instance.buzzer(times, duration)
+
+    assert str(e.value) == expected_message