Add OCR app setting migrations

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

mayan/apps/ocr/tests/test_setting_migrations.py

@@ -0,0 +1,36 @@
+from __future__ import unicode_literals
+
+from django.conf import settings
+from django.utils.encoding import force_bytes
+
+from mayan.apps.common.tests.base import BaseTestCase
+from mayan.apps.common.tests.mixins import EnvironmentTestCaseMixin
+from mayan.apps.smart_settings.classes import Setting
+from mayan.apps.storage.utils import NamedTemporaryFile
+
+from ..settings import setting_ocr_backend_arguments
+
+
+class OCRSettingMigrationTestCase(EnvironmentTestCaseMixin, BaseTestCase):
+    def test_ocr_backend_arguments_0001(self):
+
+        test_value = {'location': 'test value'}
+
+        with NamedTemporaryFile() as file_object:
+            settings.CONFIGURATION_FILEPATH = file_object.name
+            file_object.write(
+                force_bytes(
+                    '{}: {}'.format(
+                        'OCR_BACKEND_ARGUMENTS',
+                        '"{}"'.format(
+                            Setting.serialize_value(value=test_value)
+                        )
+                    )
+                )
+            )
+            file_object.seek(0)
+            Setting._config_file_cache = None
+
+            self.assertEqual(
+                setting_ocr_backend_arguments.value, test_value
+            )