put fixtures into conftest

tests/test_devserver.py

@@ -1,17 +1,8 @@
 import time
 
-import pytest
-
-from tempfile import TemporaryDirectory
 from blag import devserver
 
 
-@pytest.fixture
-def tempdir():
-    with TemporaryDirectory() as dir:
-        yield dir
-
-
 def test_get_last_modified(tempdir):
     # take initial time
     t1 = devserver.get_last_modified([tempdir])