add test for web-api use new seafile api

tests/api/test_html_repo_history_changes.py

@@ -0,0 +1,20 @@
+from django.test import RequestFactory
+
+from seahub.api2.views import html_repo_history_changes
+from seahub.test_utils import BaseTestCase
+
+class RepoTest(BaseTestCase):
+    def setUp(self):
+        # Every test needs access to the request factory.
+        self.factory = RequestFactory()
+
+        # Create an instance of a GET request.
+        self.request = self.factory.get('/foo/')
+
+        self.request.user = self.user
+        self.request.cloud_mode = False
+
+    def test_can_not_get_without_commit_id(self):
+        repo = self.repo
+        resp = html_repo_history_changes(self.request, repo.id)
+        self.assertEqual(400, resp.status_code)