tests: cleanup test code

- remove unused imports in test cases
- fix code smells and code style in conftest.py

test/test_virtual-path/test_custom_conf.py

@@ -1,5 +1,6 @@
 import pytest
 
+
 def test_default_root_response(docker_compose, nginxproxy):
     r = nginxproxy.get("http://nginx-proxy.test/")
     assert r.status_code == 418

test/test_virtual-path/test_forwarding.py

@@ -1,5 +1,3 @@
-import pytest
-
 def test_root_redirects_to_web1(docker_compose, nginxproxy):
     r = nginxproxy.get("http://www.nginx-proxy.tld/port", allow_redirects=False)
     assert r.status_code == 301

test/test_virtual-path/test_location_precedence.py

@@ -1,5 +1,3 @@
-import pytest
-
 def test_location_precedence_case1(docker_compose, nginxproxy):
     r = nginxproxy.get(f"http://foo.nginx-proxy.test/web1/port")
     assert r.status_code == 200

test/test_virtual-path/test_virtual_paths.py

@@ -3,6 +3,7 @@ from time import sleep
 import pytest
 from docker.errors import NotFound
 
+
 @pytest.mark.parametrize("stub,expected_port", [
     ("nginx-proxy.test/web1", 81),
     ("nginx-proxy.test/web2", 82),