Merge pull request #4663 from edx/jmbowman/pypi-problem-builder

Install xblock-problem-builder from PyPI

playbooks/roles/edxapp/defaults/main.yml

@@ -482,7 +482,7 @@ EDXAPP_EXTRA_REQUIREMENTS: []
 #   - name: git+https://git.myproject.org/MyProject#egg=MyProject
 EDXAPP_PRIVATE_REQUIREMENTS:
     # For Harvard courses:
-    - name: git+https://github.com/open-craft/problem-builder.git@0b3255214cbfff4a8b4a210fdf54f7a014a06402#egg=xblock-problem-builder==3.1.2
+    - name: xblock-problem-builder==3.1.3
     # Oppia XBlock
     - name: git+https://github.com/oppia/xblock.git@9f6b95b7eb7dbabb96b77198a3202604f96adf65#egg=oppia-xblock
       extra_args: -e