make version['latch'] optional

inventory_provider/routes/default.py

@@ -18,10 +18,12 @@ def after_request(resp):
 @common.require_accepts_json
 def version():
     config = current_app.config["INVENTORY_PROVIDER_CONFIG"]
-
-    return jsonify({
+    version_params = {
         'api': API_VERSION,
         'module':
-            pkg_resources.get_distribution('inventory_provider').version,
-        'latch': get_latch(get_current_redis(config))
-    })
+            pkg_resources.get_distribution('inventory_provider').version
+    }
+    latch = get_latch(get_current_redis(config))
+    if latch:
+        version_params['latch'] = latch
+    return jsonify(version_params)

test/conftest.py

@@ -141,15 +141,6 @@ def flask_config_filename():
 
 @pytest.fixture
 def mocked_redis(mocker):
-
-    MockedRedis().db['db:latch'] = json.dumps({
-        'current': 0,
-        'next': 0,
-        'this': 0,
-        'pending': False,
-        'failure': False
-    })
-
     mocker.patch(
         'inventory_provider.tasks.common.redis.StrictRedis',
         MockedRedis)