Move existing test to new test_package module

I think it's a better fit there, because the other tests all concern the
template tag itself.

Please note that the test fails for me locally.

Author: maiksprenger

tests/test_package.py

@@ -1,6 +1,17 @@
-from django.test import override_settings
+from os.path import exists, join
 from unittest.mock import patch
+
 from django.apps import apps
+from django.test import override_settings
+
+try:
+    import site
+
+    site_packages = site.getsitepackages()[0]
+except (ImportError, IndexError):
+    import sysconfig
+
+    site_packages = sysconfig.get_paths()["purelib"]
 
 @override_settings(MERMAID_USE_CDN=False)
 @patch('django_mermaid.apps.download_if_necessary')
@@ -18,4 +29,10 @@ def test_download_not_called_when_use_cdn_true(mock_download):
     app_config = apps.get_app_config('django_mermaid')
     app_config.ready()
 
-    mock_download.assert_not_called()
+    mock_download.assert_not_called()
+
+
+def test_tag_use_custom_version():
+    static_dir = join(site_packages, "django_mermaid", "static")
+    assert exists(join(static_dir, "mermaid", "8.6.3", "mermaid.js"))
+    assert exists(join(static_dir, "mermaid", "9.4.3", "mermaid.js"))

tests/test_tag.py

@@ -1,6 +1,3 @@
-from os.path import exists
-from os.path import join
-
 import pytest
 from django.conf import settings
 from django.template import Context
@@ -125,7 +122,3 @@ def test_tag_use_custom_theme_variables_with_base_theme(version, template_code):
     )
 
 
-def test_tag_use_custom_version():
-    static_dir = join(site_packages, "django_mermaid", "static")
-    assert exists(join(static_dir, "mermaid", "8.6.3", "mermaid.js"))
-    assert exists(join(static_dir, "mermaid", "9.4.3", "mermaid.js"))