Changes to global_environment_variables cause duplication

[Travis Truman]

Scenario:

Set the global_environment_variables dict to:

global_environment_variables:
    http_proxy: "http://someproxy.example.com"
    https_proxy: "http://someproxy.example.com"

Run host and container playbooks:

openstack-ansible setup-hosts.yml

Change the values of global_environment_variables dict to:

global_environment_variables:
    http_proxy: "http://adifferentproxy.example.com"
    https_proxy: "http://adifferentproxy.example.com"

Run host and container playbooks:

openstack-ansible setup-hosts.yml

Expected behavior:

/etc/environment in both the host and container look like:

http_proxy=http://adifferentproxy.example.com
https_proxy=http://adifferentproxy.example.com

Actual behavior:

/etc/environment in both the host and container look like:

http_proxy=http://someproxy.example.com
https_proxy=http://someproxy.example.com
http_proxy=http://adifferentproxy.example.com
https_proxy=http://adifferentproxy.example.com

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/309128
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-openstack_hosts/commit/?id=bc21adddac233a9fb18336cf6c830c45b685cc7d
Submitter: Jenkins
Branch: master

commit bc21adddac233a9fb18336cf6c830c45b685cc7d
Author: Travis Truman <email address hidden>
Date: Thu Apr 21 13:49:57 2016 -0400

    Template /etc/environment rather than use lineinfile

    The existing lineinfile implementation is buggy when changing and removing
    entries from the global_environment_variables dict

    Change-Id: Ic9899b1a4a72e72d0bac26eb8f650681186332e1
    Partial-Bug: #1573131

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/309517
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-lxc_container_create/commit/?id=f2646d36d89548bd7ed4154aa0ef75a86d94b7b5
Submitter: Jenkins
Branch: master

commit f2646d36d89548bd7ed4154aa0ef75a86d94b7b5
Author: Travis Truman <email address hidden>
Date: Fri Apr 22 12:58:37 2016 -0400

    Template /etc/environment rather than use lineinfile

    The existing lineinfile implementation is buggy when changing and removing
    entries from the global_environment_variables dict

    Significant refactoring of the role tests was necessary in order
    to get usable testing on the change as well as to resolve a few
    problems with the previous implementation of the role testing.

    Partial-Bug: #1573131

    Change-Id: I401763d277d179249973545e873796f9dd54049b

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/312109

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/312110

[OpenStack Infra (hudson-openstack)]

Change abandoned by Jesse Pretorius (odyssey4me) (<email address hidden>) on branch: stable/mitaka
Review: https://review.openstack.org/312109
Reason: Abandoning in favor of https://review.openstack.org/312110

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/312109
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-openstack_hosts/commit/?id=e7e0f03d1006d88b12e256e6487acc1eacd719ed
Submitter: Jenkins
Branch: stable/mitaka

commit e7e0f03d1006d88b12e256e6487acc1eacd719ed
Author: Travis Truman <email address hidden>
Date: Thu Apr 21 13:49:57 2016 -0400

    Template /etc/environment rather than use lineinfile

    The existing lineinfile implementation is buggy when changing and removing
    entries from the global_environment_variables dict

    Change-Id: Ic9899b1a4a72e72d0bac26eb8f650681186332e1
    Partial-Bug: #1573131
    (cherry picked from commit bc21adddac233a9fb18336cf6c830c45b685cc7d)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/312110
Committed: https://git.openstack.org/cgit/openstack/openstack-ansible-lxc_container_create/commit/?id=533cec28371ecbee7ddb5dd7bfdea7e8b318cbad
Submitter: Jenkins
Branch: stable/mitaka

commit 533cec28371ecbee7ddb5dd7bfdea7e8b318cbad
Author: Travis Truman <email address hidden>
Date: Fri Apr 22 12:58:37 2016 -0400

    Template /etc/environment rather than use lineinfile

    The existing lineinfile implementation is buggy when changing and removing
    entries from the global_environment_variables dict

    Significant refactoring of the role tests was necessary in order
    to get usable testing on the change as well as to resolve a few
    problems with the previous implementation of the role testing.

    Partial-Bug: #1573131
    Cherry-Pick of:
      I401763d277d179249973545e873796f9dd54049b
      and
      Ifa7ed380432f60af3c9e68c1bfa2a43dc2d65473

    Change-Id: I401763d277d179249973545e873796f9dd54049b