libxml2-dev package is needed for lxml.etree

added fedora package as well

Change-Id: I7bf34ad1842a6320536ff9ce468c5cb9f0ef3cd5
diff --git a/files/apts/glance b/files/apts/glance
index 9612267..a05e9f2 100644
--- a/files/apts/glance
+++ b/files/apts/glance
@@ -1,4 +1,5 @@
 gcc
+libxml2-dev
 python-dev
 python-eventlet
 python-routes