Allow any OID for access_method, validate OIDs at creation time, fix tests.
diff --git a/tests/test_x509_ext.py b/tests/test_x509_ext.py
index 751de08..511fad6 100644
--- a/tests/test_x509_ext.py
+++ b/tests/test_x509_ext.py
@@ -1861,7 +1861,8 @@
 
 class TestAccessDescription(object):
     def test_invalid_access_method(self):
-        with pytest.raises(ValueError):
+        # access_method can be *any* valid OID
+        with pytest.raises(TypeError):
             x509.AccessDescription("notanoid", x509.DNSName(u"test"))
 
     def test_invalid_access_location(self):