Tests: unified setup method usage.

To make fixtures accessible inside of setup methods in tests all these methods
are renamed to the "setup_method_fixture" and decorated by autouse flag.

Also all setup methods moved to the top of the files.

test/test_client_ip.py

@@ -1,3 +1,4 @@
+import pytest
 from unit.applications.lang.python import TestApplicationPython
 from unit.option import option
 
@@ -5,6 +6,10 @@ from unit.option import option
 class TestClientIP(TestApplicationPython):
     prerequisites = {'modules': {'python': 'any'}}
 
+    @pytest.fixture(autouse=True)
+    def setup_method_fixture(self):
+        self.load('client_ip')
+
     def client_ip(self, options):
         assert 'success' in self.conf(
             {
@@ -39,9 +44,6 @@ class TestClientIP(TestApplicationPython):
             headers={'Connection': 'close', 'X-Forwarded-For': xff},
         )['body']
 
-    def setup_method(self):
-        self.load('client_ip')
-
     def test_client_ip_single_ip(self):
         self.client_ip(
             {'header': 'X-Forwarded-For', 'source': '123.123.123.123'}