Upgrade to rvm 1.18.15

* Adds ruby-1.9.3-p392 & ruby-2.0.0-p0
Default rvm ruby to 1.9.3-p392
Use system ruby in .rvmrc

pivotal_workstation should not rely on a more modern Ruby verion than
the one that ships with OS X Mountain Lion. Using the system ruby seems
to be the easiest way to acheive this. We do lose gemset support
with this change, though it isn't clear to me that we need this.
Update README for soloist 1.0
Add myself as a maintainer.
Upgrade Hombrew and Use `brew` definition directly

* Remove brew_install completely
* Latest homebrew was needed to get solr,svn & zsh recipes to work
Merge pull request #239 from hiremaga/prefer_brew_to_brew_install

Upgrade Hombrew and Use `brew` definition directly
Merge pull request #236 from hiremaga/soloist-1.0

Update README for soloist 1.0
Merge pull request #235 from hiremaga/rvm-1.18.15

RVM 1.18.15 and Ruby 1.9.3-p392
Ugly hack until MySQL fixes tz
Merge pull request #234 from hiremaga/rvmrc_system

Use system ruby in .rvmrc
Use master for homebrew

Homebrew wants to live on the edge. This said it's still possible to
customize your version to a sha if you'd prefer to lock things down for
your project.