Create an ansible script for running populate_model.

Initially used for xblock configurations, but can be used for any
ConfigurationModel.

playbooks/edx-east/populate_configuration_model.yml

+#
+# edX Configuration
+#
+# github:     https://github.com/edx/configuration
+# wiki:       https://openedx.atlassian.net/wiki/display/OpenOPS
+# code style: https://openedx.atlassian.net/wiki/display/OpenOPS/Ansible+Code+Conventions
+# license:    https://github.com/edx/configuration/blob/master/LICENSE.TXT
+#
+# Usage: ansible-playbook -i lms-host-1, -e "file=/path/to/json/file" -e "user=username"
+#
+# Overview:
+# This executes the "populate_model" management command to populate a ConfigurationModel with
+# data from the supplied JSON file.
+#
+# The username of an existing user must be specified to indicate who is performing the operation.
+#
+# JSON file format should be:
+#
+#    { "model": "config_models.ExampleConfigurationModel",
+#      "data":
+#        [
+#          { "enabled": True,
+#            "color": "black"
+#            ...
+#          },
+#          { "enabled": False,
+#            "color": "yellow"
+#            ...
+#          },
+#          ...
+#        ]
+#   }
+#
+
+- hosts: all
+  vars:
+    python_path: /edx/bin/python.edxapp
+    manage_path: /edx/bin/manage.edxapp
+  tasks:
+    - name: Manage xblock configurations
+      shell: >
+        {{ python_path }} {{ manage_path }} lms --settings=aws
+        populate_model -f {{ file | quote }} -u {{ user }}
+      register: command_result
+      changed_when: "'Import complete, 0 new entries created' not in command_result.stdout"
+    - debug: msg="{{ command_result.stdout }}"