remove certforward feature

The certforward feature was implemented to support #gotofail,
which only works on unpatched iOS devices. Given that many apps don't
support iOS 7 anymore, jailbreak+ssl killswitch is usually the better option.
By removing certforward, we can make netlib a pure python module again,
which significantly simplifies distribution.

test/test_server.py

@@ -757,14 +757,6 @@ class TestIncompleteResponse(tservers.HTTPProxTest):
         assert self.pathod("200").status_code == 502
 
 
-class TestCertForward(tservers.HTTPProxTest):
-    certforward = True
-    ssl = True
-
-    def test_app_err(self):
-        tutils.raises("handshake error", self.pathod, "200:b@100")
-
-
 class TestUpstreamProxy(tservers.HTTPUpstreamProxTest, CommonMixin, AppMixin):
     ssl = False
 

test/tservers.py

@@ -89,7 +89,6 @@ class ProxTestBase(object):
     no_upstream_cert = False
     authenticator = None
     masterclass = TestMaster
-    certforward = False
 
     @classmethod
     def setupAll(cls):
@@ -131,7 +130,6 @@ class ProxTestBase(object):
             no_upstream_cert = cls.no_upstream_cert,
             cadir = cls.cadir,
             authenticator = cls.authenticator,
-            certforward = cls.certforward,
             ssl_ports=([cls.server.port, cls.server2.port] if cls.ssl else []),
             clientcerts = tutils.test_data.path("data/clientcert") if cls.clientcerts else None
         )