[mod] use tests/unit/settings/test_settings.yml in unit tests

In unit tests settings from

    searx/settings.yml

and the user settings from:

    unit/settings/test_settings.yml

are used.  In the latter, settings can be activated that are needed in the unit
test but should not activated by default in production.

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

tests/unit/__init__.py

@@ -0,0 +1,6 @@
+import os
+from os.path import dirname, sep, abspath
+
+# In unit tests the user settings from unit/settings/test_settings.yml are used.
+os.environ['SEARX_SETTINGS_PATH'] = abspath(
+    dirname(__file__) + sep + 'settings' + sep + 'test_settings.yml')

tests/unit/settings/test_settings.yml

@@ -0,0 +1,5 @@
+# This SearXNG setup is used in unit tests
+
+use_default_settings: true
+search:
+  formats: [html, csv, json, rss]