Added code to the end of aws.py so that COUNTRIES_OVERRIDE value can be fetched from environment. That way country list can be modified by defining the value in server-vars.yml with EDXAPP_COUNTRIES_OVERRIDE dictionary.
Added code to the end of aws.py so that COUNTRIES_OVERRIDE value can be
fetched from environment. That way country list can be modified by
defining the value in server-vars.yml with EDXAPP_COUNTRIES_OVERRIDE
dictionary.

A sample dictionary is like that. Setting null removes the country from
list.
EDXAPP_COUNTRIES_OVERRIDE:
XX: "New name for existing country"
XY: null
XZ: "Add new country"

synergeticsedx/deployment-wipro,synergeticsedx/deployment-wipro,naresh21/synergetics-edx-platform,synergeticsedx/deployment-wipro,synergeticsedx/deployment-wipro,naresh21/synergetics-edx-platform,naresh21/synergetics-edx-platform,naresh21/synergetics-edx-platform