Fix import issues with python3

Relative imports are different and some modules were renamed.

Author: SpamapS

src/saml2/assertion.py

@@ -6,7 +6,7 @@
 import re
 from saml2.saml import NAME_FORMAT_URI
 import six
-import xmlenc
+from saml2 import xmlenc
 
 from saml2 import saml
 

src/saml2/client_base.py

@@ -6,8 +6,8 @@
 to conclude its tasks.
 """
 import threading
-from urllib import urlencode
-from urlparse import urlparse
+from six.moves.urllib.parse import urlencode
+from six.moves.urllib.parse import urlparse
 import six
 
 from saml2.entity import Entity
@@ -25,7 +25,7 @@
 import time
 from saml2.soap import make_soap_enveloped_saml_thingy
 
-from urlparse import parse_qs
+from six.moves.urllib.parse import parse_qs
 
 from saml2.s_utils import signature, UnravelError, exception_trace
 from saml2.s_utils import do_attributes

src/saml2/ident.py

@@ -4,8 +4,8 @@
 import six
 
 from hashlib import sha256
-from urllib import quote
-from urllib import unquote
+from six.moves.urllib.parse import quote
+from six.moves.urllib.parse import unquote
 from saml2 import SAMLError
 from saml2.s_utils import rndstr
 from saml2.s_utils import PolicyError

src/saml2/request.py

@@ -1,6 +1,6 @@
 import logging
 
-from attribute_converter import to_local
+from saml2.attribute_converter import to_local
 from saml2 import time_util, BINDING_HTTP_REDIRECT
 from saml2.s_utils import OtherError
 

tests/test_30_mdstore.py

@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 import datetime
 import re
-from urllib import quote_plus
+from six.moves.urllib.parse import quote_plus
 from saml2.httpbase import HTTPBase
 
 from saml2.mdstore import MetadataStore, MetaDataMDX