Remove boilerplate zuul.conf from test fixtures

Change-Id: I288f17e0a5242545b4a1841e99008e23e1f154b8
diff --git a/tests/test_v3.py b/tests/test_v3.py
index b86b630..8425383 100644
--- a/tests/test_v3.py
+++ b/tests/test_v3.py
@@ -29,7 +29,7 @@
 class TestMultipleTenants(ZuulTestCase):
     # A temporary class to hold new tests while others are disabled
 
-    config_file = 'config/multi-tenant/zuul.conf'
+    tenant_config_file = 'config/multi-tenant/main.yaml'
 
     def test_multiple_tenants(self):
         A = self.fake_gerrit.addFakeChange('org/project1', 'master', 'A')
@@ -67,7 +67,7 @@
 class TestInRepoConfig(ZuulTestCase):
     # A temporary class to hold new tests while others are disabled
 
-    config_file = 'config/in-repo/zuul.conf'
+    tenant_config_file = 'config/in-repo/main.yaml'
 
     def setup_repos(self):
         in_repo_conf = textwrap.dedent(
@@ -100,7 +100,7 @@
 
 
 class TestProjectTemplate(ZuulTestCase):
-    config_file = 'config/project-template/zuul.conf'
+    tenant_config_file = 'config/project-template/main.yaml'
 
     def test(self):
         A = self.fake_gerrit.addFakeChange('org/project', 'master', 'A')