Added support for setting file descriptor limits.
Add support for making use of operating system package managers.
Target version 2.2.4 and above of the yum cookbook because earlier
versions contain a broken broken test stub that breaks test-kitchen.
Update Opscode Vagrant boxes so that they are provisionerless. Now
Test Kitchen installs Chef. Also, increase default memory to 512MB.
Merge pull request #17 from basho/hc-use-package-managers

Add support for making use of package managers.