Drop lxml dependency

Fixes bug #1068290

Removed lxml from tools/pip-requires
Removed usused method _to_xml() in quantum.wsgi.XMLDictSerializer

Change-Id: I3410fd8645739abfd853f71efcbb354b58677b18

quantum/wsgi.py

@@ -24,7 +24,6 @@ from xml.parsers import expat
 
 import eventlet.wsgi
 eventlet.patcher.monkey_patch(all=False, socket=True)
-from lxml import etree
 import routes.middleware
 import webob.dec
 import webob.exc
@@ -310,11 +309,6 @@ class XMLDictSerializer(DictSerializer):
             link_nodes.append(link_node)
         return link_nodes
 
-    def _to_xml(self, root):
-        """Convert the xml object to an xml string."""
-        # we use lxml here instead of xml.minidom for performance reasons
-        return etree.tostring(root, encoding='UTF-8', xml_declaration=True)
-
 
 class ResponseHeaderSerializer(ActionDispatcher):
     """Default response headers serialization"""

tools/pip-requires

@@ -8,7 +8,6 @@ greenlet>=0.3.1
 httplib2
 iso8601>=0.1.4
 kombu==1.0.4
-lxml
 netaddr
 python-quantumclient>=2.0
 pyudev