Upgrade lxml to use pre-built pkg - no longer requires Cython.

common/lib/capa/capa/responsetypes.py

@@ -2468,8 +2468,7 @@ class CustomResponse(LoncapaResponse):
             msg = msg.replace('<', '<')
 
             # Use etree to prettify the HTML
-            msg = etree.tostring(fromstring_bs(msg, convertEntities=None),
-                                 pretty_print=True)
+            msg = etree.tostring(fromstring_bs(msg), pretty_print=True)
 
             msg = msg.replace('
', '')
 

requirements/edx/base.txt

@@ -115,8 +115,7 @@ pyuca==1.1
 wrapt==1.10.5
 zendesk==1.1.1
 
-# This needs to be installed *after* Cython, which is in pre.txt
-lxml==3.4.4
+lxml==3.8.0
 
 # Used for shopping cart's pdf invoice/receipt generation
 reportlab==3.1.44