Add another cleanup test and fix celery test broker

Turns out celery doesn't like in-memory sql backends, but has a
built-in memory broker. Use that instead and remove sqlalchemy
requirement

cabot/cabotapp/tests/tests_basic.py

@@ -990,6 +990,22 @@ class TestCleanUpTask(LocalTestCase):
         tasks.clean_db(batch_size=1)
         self.assertEqual(StatusCheckResult.objects.all().count(), initial_results)
 
+    def test_cleanup_single_batch(self):
+        with self.settings(CELERY_ALWAYS_EAGER=False):
+            initial_results = StatusCheckResult.objects.all().count()
+
+            for i in range(2):
+                StatusCheckResult(
+                    status_check=self.graphite_check,
+                    time=timezone.now() - timedelta(days=61),
+                    time_complete=timezone.now() - timedelta(days=61),
+                    succeeded=False
+                ).save()
+
+            self.assertEqual(StatusCheckResult.objects.all().count(), initial_results + 2)
+            tasks.clean_db(batch_size=1)
+            self.assertEqual(StatusCheckResult.objects.all().count(), initial_results + 1)
+
 
 class TestMinimizeTargets(LocalTestCase):
     def test_null(self):

conf/test.env

@@ -1,6 +1,6 @@
 DATABASE_URL=sqlite://:memory:
 
-CELERY_BROKER_URL=sqla+sqlite://:memory:
+CELERY_BROKER_URL=memory://
 CELERY_RESULT_BACKEND=db+sqlite://:memory:
 CELERY_ALWAYS_EAGER=true
 

requirements-dev.txt

@@ -1,5 +1,4 @@
 coverage==4.2
 django_coverage_plugin==1.3.1
 mock==1.0.1
-sqlalchemy==1.1.5
 ipdb