This reverts commit 2bfaacd1.

Fixes #6821

Also added a new integration test for assemble using local assembly
with a delimiter.

Also adds an integration test for authorized_key for future validation.

Fixes #6700

Fixes #6678
Fixes #6670

Changes include:

 * Update Makefile to use credentials.yml when it exists
 * Add details on the use of the credentials.yml file to README.md.
 * Update credentials.template comments

The `apt` and `yum` modules will automatically install python dependencies.
This change updates the existing integration tests to test whether auto-install
of dependencies is functioning properly.

- unified set attribute functions ... not sure why 2 identical functions
exist with diff names, now there are 3 while i repoint all modules to 1
- fixed issue with symlinks being created w/o existing src when force=no
- refactored conditionals, simplified where possible
- added tests for symlink to nonexistant source, with both force options
- made symlink on existing attomic (force)

Tests several ways to specify the repository.  For every repo added, the test
asserts that:

 * the apt-cache was updated as expected (depends on `update_cache` parameter)
 * the PPA key was installed (depends on `repo` format)

To support parallel cloud test execution, create and provide a random string to
cloud integration tests.  The variable 'resource_prefix' can be used in cloud
roles and during resource cleanup to safely create/destroy cloud-based
resources.

Additional changes include:

 * The roles test_ec2_key and test_ec2_group were updated to use to
 {{resource_prefix}}.

 * Additionally, the Makefile was updated to set resource_prefix to a random
 string.  The Makefile will also use 'resource_prefix' during cloud_cleanup.

 * All test_ec2* roles were updated to add 'setup_ec2' as a role dependency.

Testers may override the inventory and vars-file using the environment
variables 'INVENTORY' and 'VARS_FILE'.

Includes coverage for accept_hostkey and additional scm URL formats.

Closes GH-5354.

Forklift copy logic into unarchive. Provides integration unit tests.

The 'service' utility was unable to find the 'ansible_test' service due to an
unexpected filename.  This patch corrects the filename and adjusts the
permissions to match other service scripts within /etc/init/.

Redhat != RedHat

This fixes integration tests when run on a RHEL system.  Oddly, the
ansible_distribution='RedHat' when run on RHEL.

Remove the legacy templating code, which was guarded by deprecation warnings in the previous two releases, and undocumented for a long time.  use {{ foo }} to access variables instead of ${foo} or $foo.

Some systems that we are testing on may not have /etc/motd. So we need to create a file that we can control and use that for the further tests.