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/unit/applications/lang/go.py

@@ -2,11 +2,11 @@ import os
 import shutil
 import subprocess
 
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 
 
-class TestApplicationGo(TestApplicationProto):
+class ApplicationGo(ApplicationProto):
     @staticmethod
     def prepare_env(script, name='app', static=False):
         try:
@@ -88,7 +88,7 @@ replace unit.nginx.org/go => {replace_path}
             executable = f"/go/{name}"
             static_build = True
 
-        TestApplicationGo.prepare_env(script, name, static=static_build)
+        ApplicationGo.prepare_env(script, name, static=static_build)
 
         conf = {
             "listeners": {"*:7080": {"pass": f"applications/{script}"}},

test/unit/applications/lang/java.py

@@ -4,12 +4,13 @@ import shutil
 import subprocess
 
 import pytest
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 
 
-class TestApplicationJava(TestApplicationProto):
-    application_type = "java"
+class ApplicationJava(ApplicationProto):
+    def __init__(self, application_type='java'):
+        self.application_type = application_type
 
     def prepare_env(self, script):
         app_path = f'{option.temp_dir}/java'

test/unit/applications/lang/node.py

@@ -1,14 +1,15 @@
 import shutil
 from urllib.parse import quote
 
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 from unit.utils import public_dir
 
 
-class TestApplicationNode(TestApplicationProto):
-    application_type = "node"
-    es_modules = False
+class ApplicationNode(ApplicationProto):
+    def __init__(self, application_type='node', es_modules=False):
+        self.application_type = application_type
+        self.es_modules = es_modules
 
     def prepare_env(self, script):
         # copy application

test/unit/applications/lang/perl.py

@@ -1,9 +1,10 @@
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 
 
-class TestApplicationPerl(TestApplicationProto):
-    application_type = "perl"
+class ApplicationPerl(ApplicationProto):
+    def __init__(self, application_type='perl'):
+        self.application_type = application_type
 
     def load(self, script, name='psgi.pl', **kwargs):
         script_path = f'{option.test_dir}/perl/{script}'

test/unit/applications/lang/php.py

@@ -1,12 +1,13 @@
 import os
 import shutil
 
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 
 
-class TestApplicationPHP(TestApplicationProto):
-    application_type = "php"
+class ApplicationPHP(ApplicationProto):
+    def __init__(self, application_type='php'):
+        self.application_type = application_type
 
     def load(self, script, index='index.php', **kwargs):
         script_path = f'{option.test_dir}/php/{script}'

test/unit/applications/lang/python.py

@@ -2,13 +2,14 @@ import os
 import shutil
 from urllib.parse import quote
 
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 
 
-class TestApplicationPython(TestApplicationProto):
-    application_type = "python"
-    load_module = "wsgi"
+class ApplicationPython(ApplicationProto):
+    def __init__(self, application_type='python', load_module='wsgi'):
+        self.application_type = application_type
+        self.load_module = load_module
 
     def load(self, script, name=None, module=None, **kwargs):
         if name is None:

test/unit/applications/lang/ruby.py

@@ -1,12 +1,13 @@
 import shutil
 
-from unit.applications.proto import TestApplicationProto
+from unit.applications.proto import ApplicationProto
 from unit.option import option
 from unit.utils import public_dir
 
 
-class TestApplicationRuby(TestApplicationProto):
-    application_type = "ruby"
+class ApplicationRuby(ApplicationProto):
+    def __init__(self, application_type='ruby'):
+        self.application_type = application_type
 
     def prepare_env(self, script):
         shutil.copytree(