updating branch for edx-platform and make package faster

playbooks/roles/edxapp/tasks/main.yml

@@ -29,7 +29,8 @@
   - update
 
 - name: install a bunch of system packages on which LMS and CMS rely
-  apt: pkg={{','.join(lms_debian_pkgs)}} state=present
+  apt: pkg={{item}} state=present
+  with_items: lms_debian_pkgs
   tags:
   - lms
   - cms

playbooks/roles/edxapp/vars/main.yml

@@ -184,7 +184,7 @@ edxapp_theme_version: 'HEAD'
 
 # make this the public URL instead of writable
 lms_source_repo: https://github.com/edx/edx-platform.git
-lms_version: 'HEAD'
+lms_version: '5b16fbe3692d984517d870f5eec4c48c9bf1fe16'
 local_requirements_file:  "{{ edx_platform_code_dir }}/requirements/edx/local.txt"
 pre_requirements_file:    "{{ edx_platform_code_dir }}/requirements/edx/pre.txt"
 post_requirements_file:   "{{ edx_platform_code_dir }}/requirements/edx/post.txt"