Update bootstrap database and ruby

In order to make this cookbook's parts installable across multiple nodes, this commit changes the recipes to be less dependent of each other. This allows the database portions and the app portions to be fully separated onto different nodes. In addition it adds some significant improvement in converge time for a node by switching out ruby_build for rvm. This pulls down a binary version of ruby instead of compiling it by hand. And it switches to compiling nginx so that we get a reasonably new version instead of being at the mercy of the package version.