added tests for all formatters; stylecheck workflow now also checks in tests now

tests/formatters/tests_include_formatter.py

@@ -0,0 +1,17 @@
+from unittest import TestCase
+from bs4 import BeautifulSoup
+from html_to_django.formatters import include_formatter
+
+
+class IncludeTests(TestCase):
+    def test_basic(self) -> None:
+        soup = BeautifulSoup('<div dj-include="template_name"></div>', "html.parser")
+        include_formatter.format(soup)
+        expected_result = '<div>{% include "template_name" %}</div>'
+        self.assertEqual(expected_result, str(soup))
+
+    def test_with_content(self) -> None:
+        soup = BeautifulSoup('<div dj-include="template_name">Test</div>', "html.parser")
+        include_formatter.format(soup)
+        expected_result = '<div>{% include "template_name" %}</div>'
+        self.assertEqual(expected_result, str(soup))