pytest: fix collection warnings via __test__=False

Fixes

> "cannot collect test class %r because it has a __init__ constructor

Ref: pytest-dev/pytest#2007

Author: blueyed

paste/fixture.py

@@ -90,13 +90,14 @@ def reset(self):
             "SMTP connection not quit")
         self.__class__.existing = None
 
+
 class AppError(Exception):
     pass
 
+
 class TestApp(object):
 
-    # for py.test
-    disabled = True
+    __test__ = False  # Ignore with pytest test collection.
 
     def __init__(self, app, namespace=None, relative_to=None,
                  extra_environ=None, pre_request_hook=None,
@@ -494,10 +495,10 @@ def writelines(self, lines):
     def getvalue(self):
         return self.captured.getvalue()
 
+
 class TestResponse(object):
 
-    # for py.test
-    disabled = True
+    __test__ = False  # Ignore with pytest test collection.
 
     """
     Instances of this class are return by `TestApp
@@ -884,10 +885,10 @@ def showbrowser(self):
         url = 'file:' + fn.replace(os.sep, '/')
         webbrowser.open_new(url)
 
+
 class TestRequest(object):
 
-    # for py.test
-    disabled = True
+    __test__ = False  # Ignore with pytest test collection.
 
     """
     Instances of this class are created by `TestApp
@@ -1331,8 +1332,7 @@ class TestFileEnvironment(object):
     scripts will be run.
     """
 
-    # for py.test
-    disabled = True
+    __test__ = False  # Ignore with pytest test collection.
 
     def __init__(self, base_path, template_path=None,
                  script_path=None,