Tests: get rid of classes in test files.

Class usage came from the unittest framework and it was always redundant
after migration to the pytest.  This commit removes classes from files
containing tests to make them more readable and understandable.

test/conftest.py

@@ -15,7 +15,7 @@ from multiprocessing import Process
 import pytest
 from unit.check.discover_available import discover_available
 from unit.check.check_prerequisites import check_prerequisites
-from unit.http import TestHTTP
+from unit.http import HTTP1
 from unit.log import Log
 from unit.log import print_log_on_assert
 from unit.option import option
@@ -82,7 +82,7 @@ _fds_info = {
         'skip': False,
     },
 }
-http = TestHTTP()
+http = HTTP1()
 is_findmnt = check_findmnt()
 
 
@@ -113,15 +113,16 @@ def pytest_configure(config):
 
 
 def pytest_generate_tests(metafunc):
-    cls = metafunc.cls
+    module = metafunc.module
     if (
-        not hasattr(cls, 'application_type')
-        or cls.application_type == None
-        or cls.application_type == 'external'
+        not hasattr(module, 'client')
+        or not hasattr(module.client, 'application_type')
+        or module.client.application_type is None
+        or module.client.application_type == 'external'
     ):
         return
 
-    type = cls.application_type
+    app_type = module.client.application_type
 
     def generate_tests(versions):
         if not versions:
@@ -133,7 +134,7 @@ def pytest_generate_tests(metafunc):
         for version in versions:
             option.generated_tests[
                 f'{metafunc.function.__name__} [{version}]'
-            ] = f'{type} {version}'
+            ] = f'{app_type} {version}'
 
     # take available module from option and generate tests for each version
 
@@ -149,7 +150,7 @@ def pytest_generate_tests(metafunc):
             elif version == 'any':
                 option.generated_tests[
                     metafunc.function.__name__
-                ] = f'{type} {available_versions[0]}'
+                ] = f'{app_type} {available_versions[0]}'
             elif callable(version):
                 generate_tests(list(filter(version, available_versions)))