Use caching for leaderboard

Fix loading step CSS location

openassessment/xblock/leaderboard_mixin.py

@@ -60,12 +60,14 @@ class LeaderboardMixin(object):
             template_path (string), tuple of context (dict)
         """
 
+        # Retrieve top scores from the submissions API
+        # Since this uses the read-replica and caches the results,
+        # there will be some delay in the request latency.
         scores = sub_api.get_top_submissions(
             student_item_dict['course_id'],
             student_item_dict['item_id'],
             student_item_dict['item_type'],
-            self.leaderboard_show,
-            use_cache=False
+            self.leaderboard_show
         )
         for score in scores:
             if 'text' in score['content']:

openassessment/xblock/static/sass/oa/utilities/_developer.scss

@@ -1096,7 +1096,6 @@
   }
 
   .step__title {
-    width: 100%;
 
     .wrapper--copy{
       margin-left: 0;

requirements/base.txt

@@ -6,7 +6,7 @@
 git+https://github.com/edx/XBlock.git@fc5fea25c973ec66d8db63cf69a817ce624f5ef5#egg=XBlock
 git+https://github.com/edx/xblock-sdk.git@643900aadcb18aaeb7fe67271ca9dbf36e463ee6#egg=xblock-sdk
 
-edx-submissions>=0.0.6,<0.1.0
+edx-submissions>=0.0.7,<0.1.0
 
 # Third Party Requirements
 boto>=2.13.0,<3.0.0