Only use @pytest.fixture decorator once

This is now required in pytest >= 3.6

See pytest-dev/pytest#3518

Fixes #49

Author: hroncok

pytest_httpbin/plugin.py

@@ -36,6 +36,6 @@ def class_based_httpbin_secure(request, httpbin_secure):
     request.cls.httpbin_secure = httpbin_secure
 
 
-@pytest.fixture(scope='function')
+@pytest.fixture(autouse=True, scope='function')
 def httpbin_ca_bundle(monkeypatch):
     monkeypatch.setenv('REQUESTS_CA_BUNDLE', certs.where())

tests/conftest.py

@@ -1,6 +1,4 @@
 import pytest
 
+# we import this to make sure that autouse is known from the beginning
 from pytest_httpbin.plugin import httpbin_ca_bundle
-
-
-pytest.fixture(autouse=True)(httpbin_ca_bundle)