patchwork: update for django 1.11 and fix versions for ldap

The rest of the code is good to go for django 1.11, so let's make
it official.  Also we need to set version for an older
django-auth-ldap until we are ready to move to python3.

Change-Id: I5323259147658a7b0118c1292653394266a474cf
diff --git a/requirements.txt b/requirements.txt
index 6c97570..010a63a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,5 +5,5 @@
 dulwich==0.19.6
 mock
 flake8
-python-ldap
-django-auth-ldap
+python-ldap==3.3.1
+django-auth-ldap==1.6.1