Fixes for centos versions

[garethr]

While working on Centos support for https://github.com/garethr/riemann-vagrant I noticed that just using:

include java

Would fail on Centos 5.8 and 6.3 (using the Puppetlabs provided vagrant boxes) with an incorrect package name. The README indicates this module supports 5.3.

Checking those two boxes using yum seems to indicate that the openjdk packages are available so I've added additional logic to detect those specific versions of Centos and if found choose a relevant package in to the same way as the ubuntu logic.

I've also added tests just for this functionality (the module previously had no test suite). Two of the tests verify the backwards compatibility for 5.3, the other two the new (working) behaviour for 5.8. and 6.3.

[brettporter]

Hi Gareth,

I've merged this, with some changes. First, there had been some underlying changes in the module I needed to update for.

For the defaults, I had a look in the CentOS Vault, and AFAICT, only java-1.6.0-openjdk was offered up until 6.3 added 1.7.0, and openjdk was available in 5.3 via updates - so I set that default appropriately. I used versioncmp, so it wasn't hard-coded to the two releases.

Hope that makes sense for what you needed.

For 5.2 and prior the package would need to be supplied, but I didn't add any special case to the conditional since those weren't previously supported.