Upgrade elasticsearch-dsl.

* this will in turn restrict the elasticsearch library to a compatible version
* added unit test for unicode character cohort filtering

analytics_data_api/v0/models.py

@@ -336,7 +336,7 @@ def get_users_in_course(
             search.query.must.append(Q('multi_match', query=text_search, fields=['name', 'username', 'email']))
 
         # construct the sort hierarchy
-        search = search.sort(*[
+        search_request = search.sort(*[
             {
                 sort_policy['order_by']: {
                     'order': sort_policy['sort_order'],
@@ -347,7 +347,7 @@ def get_users_in_course(
             for sort_policy in sort_policies
         ])
 
-        return search
+        return search_request
 
     @classmethod
     def get_course_metadata(cls, course_id):

analytics_data_api/v0/tests/views/test_learners.py

@@ -1,3 +1,5 @@
+# -*- coding: utf-8 -*-
+
 import copy
 import datetime
 from itertools import groupby
@@ -272,6 +274,7 @@ def test_data(self):
         ('cohort', 'a', 'cohort', 'a', True),
         ('cohort', 'a', 'cohort', '', True),
         ('cohort', 'a', 'cohort', 'b', False),
+        ('cohort', u'Ich möchte Brot zu essen.', 'cohort', u'Ich möchte Brot zu essen.', True),
         ('enrollment_mode', 'a', 'enrollment_mode', 'a', True),
         ('enrollment_mode', 'a', 'enrollment_mode', '', True),
         ('enrollment_mode', 'a', 'enrollment_mode', 'b', False),

requirements/base.txt

@@ -5,7 +5,7 @@ djangorestframework==2.4.4			# BSD
 django-rest-swagger==0.2.8  		# BSD
 djangorestframework-csv==1.3.3		# BSD
 django-countries==3.2               # MIT
-elasticsearch-dsl==0.0.9            # Apache 2.0
+elasticsearch-dsl==0.0.11           # Apache 2.0
 
 # markdown is used by swagger for rendering the api docs
 Markdown==2.6    					# BSD