COOK-2360: don't overwrite the epel repo if it already exists

commit 89e6c61b559caa1878eebf374ba971842111 changed the behavior of
the epel recipe to create instead of adding the epel repo file.  This
caused the file to be overwritten which changes the behavior from
previous.

COOK-2196 makes no mention of the need for this change.
[COOK-2639] - Add in yum epel baseurl attribute

  * Add in an attribute for epel to use for baseurl
add yum::elrepo.
Merge pull request #38 from jwitrick/master

Stop recipe from using url as mirrorlist
[COOK-2663] - add metadata_expire

 * Extend the LWRP to include metadata_expire
 * Update the template file for the expire setting
Merge branch 'COOK-2663'
Merge pull request #40 from tily/COOK-2741

COOK-2741: yum::elrepo
remove Gemfile, Vagrantfile, not used by tk1.0
[COOK-2751] Bump ius_release to 1.0-11
Merge pull request #41 from opscode-cookbooks/ssd/COOK-2751

[COOK-2751] Bump ius_release to 1.0-11
- added the type param to the lwrp
- added missing comma
- fixed typos and added the template var for type
Merge branch 'feature/add-type-param' into develop
- added extra attributes to the README.md
Merge branch 'release/2.2.1'
[COOK-2946] - update tests, test kitchen support

This commit updates the baseboxes used for Test Kitchen to be
provisionerless, requiring use of the chef-omnibus package for
installation. This is handled in the .kitchen.yml file. It also
updates the versions to the latest released CentOS 5.9 and 6.4.

The "test cookbook" is removed, being replaced by a single "test"
recipe. The multiple suites are replaced with a single test suite. The
functionality of the various repository recipes are isolated to the
individual files that they manage, so they can be tested safely
together.

In testing, it was revealed that the IUS release attribute was
outdated, and needed to be incremented.

A new helper is added to check that repositories are enabled according
to yum itself.
Merge pull request #43 from opscode-cookbooks/COOK-2946

[COOK-2946] - update tests, test kitchen support
release v2.2.2
increment version for development