Add Parse.com credentials for the CMS

Used for sending mobile push messages.

playbooks/roles/edxapp/defaults/main.yml

@@ -479,6 +479,8 @@ EDXAPP_PROFILE_IMAGE_SECRET_KEY: placeholder_secret_key
 EDXAPP_PROFILE_IMAGE_MAX_BYTES: 1048576
 EDXAPP_PROFILE_IMAGE_MIN_BYTES: 100
 
+EDXAPP_PARSE_KEYS: {}
+
 #-------- Everything below this line is internal to the role ------------
 
 #Use YAML references (& and *) and hash merge <<: to factor out shared settings
@@ -841,6 +843,7 @@ cms_auth_config:
             - *edxapp_generic_draft_modulestore
 # Commented for now so that it can be tested first: LMS-11258
 #            - *edxapp_generic_xml_modulestore
+  PARSE_KEYS: "{{ EDXAPP_PARSE_KEYS }}"
 cms_env_config:
   <<: *edxapp_generic_env
   SITE_NAME:  "{{ EDXAPP_CMS_SITE_NAME }}"