Adds python role, which installs python 2.7 using raw ansible

The python role is prepended to edx_sandbox.yml and edx-stateless.yml in a
prefix playbook, so that gather_facts can be "no".

If you picked 16.04 from the dropdown, we'd skip the userdata

This means no python, and no build.  Instead, only zero out the
userdata when doing full_edx_installation which assumes a pre-built AMI.

Fix a comment about 12.04

Neo4j heap size override

prefix migration output with the database name

The production-requirements target will now be responsible for installing npm/bower dependencies.

ECOM-6590

The nodeenv dependency is now installed by the Ansible play, rather than relying on the library being in the code base's requirements. This will allow us to better separate the installation of Python and Node/Bower dependencies.

ECOM-6590

temp add stop-automatic-updates to packer scripts

remove systemctl calls to release dpkg lock

We use to constrict our builds to PRs, similar to edx-platform

temporarily install google chrome stable

disable auto apt updates in xenial

Update credentials playbook

add fb and tw accounts to generic_env_config

Adds COMMON_EDXAPP_SETTINGS

* Default value is 'aws' (unchanged)
* Used by EDXAPP_SETTINGS, gitreload_env.DJANGO_SETTINGS, and demo_edxapp_settings variables

Conditionally adds postfix_queue role to edx_sandbox.yml

ECOM-5776

Ready for deploying Mongo 3.2

Feanil/ecom worker 16.04

Add a flag to easily turn on/off the logging.

Feanil/update aws cli