Replace deprecated yield_fixture with equivalent to silence warning (g…

…oogle#1220)

conftest.py

@@ -37,7 +37,7 @@
 
 
 # Give this a short name since it is a fixture.
-@pytest.yield_fixture
+@pytest.fixture
 def db():  # pylint: disable=invalid-name
     """Connect to the SQLite database and create all the expected tables."""
     db_utils.initialize()
@@ -61,7 +61,7 @@ def set_sqlite_pragma(connection, _):
     cursor.close()
 
 
-@pytest.yield_fixture
+@pytest.fixture
 def environ():
     """Patch environment."""
     # TODO(metzman): Make sure this is used by all tests that modify the

experiment/build/test_builder.py

@@ -82,7 +82,7 @@ def test_build_all_measurers(_, mocked_build_measurer,
         assert not result
 
 
-@pytest.yield_fixture
+@pytest.fixture
 def builder_integration(experiment):
     """Fixture for builder.py integration tests that uses an experiment fixture
     and makes the number of build retries saner by default."""