Added rvm support.

Support rum based installs of 1.9.3. Couldn’t get the brew version to
install correctly on Yosemite so used rvm, which worked swimmingly.
Updated with new brew install path

Homebrew changed their master install download path.
Merge pull request #29 from FreedomCoder/master

Updated with new brew install path
Merge pull request #25 from atyoung/rvm-support

Added rvm support.
Updated for changes in yosemite, changes in RVM, Changes in Nokogiri and set proper permissions in linux.
Updated the name of the ruby installed by RVM
Updated the version number
Bumped to Ruby 1.9.3-p550 to address CVE-2014-8080, Next week I will test and validate when 2.1 support is added.
Merging in local changes