OPS-1593 As an operator, I want sudo_user converted to become user in roles and plays, for compatibility with Ansible 2.x

The headers were pointing to the old github wiki. Since we've officially
moved to Confluence, these links should be updated.

If a git version is specified as a branch, and the commit referred to is
already on the local working tree, but the branch is not, then the
checkout will fail.

This is because the Ansible 1.9.3 module would check to see if the
commit was already present, and if so, did not fetch. This meant the
branch wasn't defined in the local working tree.

This can happen if you make a branch but there aren't any changes on the
branch.

syntax

Making version handling consistent

whitespace

removing unrelated change.

reverting quotes

Don't override the versions is server-vars.yml.

Moving order back to before, adding a stat to check if file exists

Correcting use of stat conditional

Typo

Removing EDX_ANSIBLE_DUMP_VARS from create backup copy

Using file instead of copy module

using copy / backup module

Adding back logic to check if file exists

Moving tasks order, file has to be created first before being copied

Moving order back to before, adding a stat to check if file exists

Correcting use of stat conditional

Typo

Removing EDX_ANSIBLE_DUMP_VARS from create backup copy

Using file instead of copy module

using copy / backup module

Adding back logic to check if file exists

Logic to make sure that backup of server-var.yml works

Moving order back to before, adding a stat to check if file exists

Correcting use of stat conditional

Typo

removing sync'd folder for /vagrant

change identity file default to none

removing check for git identity

typo

typo

adding python-yaml for dumping vars

certs settings changes for local disk generation

adding var dump var

adding template for certs

adding certs to default sites

adding 400 condition to the certs nginx template

updating update script for certs, removing discern

adding cert to help

giving www-data write permission to the web root

typo

adding download url

fixing web root

adding certs download url

adding more config for cert template dir, verify url

moving extra vars into the vagrantfile

adding verify url to vagrantfile

syntax

look for valid.html

adding ownertrust export

adding the trust import

removing skip-tags for reconfigure

upgrading to latest released ansible

adding carriage return to owner trust

setting cert urls in extra vars

moving extra vars to vagrantfile

adding new accept_hostkey parameter to all git calls

set key_file

changing dir for userknownhostsfile

adding more verbosity

changing knownhostsfile in environment

don't use userknownhostsfile

setting accept_hostkey back to yes

adding .ssh dirs for the 1.5 git module

adding certs nginx site

Make it easier to use a local pypi mirror in the roles listed above

This modifies the edx_ansible role to dump a clean var
file on disk that can be used for subsequent update runs
so that config vars will not be lost

also changes the ansible tmp directory to /var/tmp which is a better
location than using $HOME (used for debugging mostly)