Skiima: fixes issues with rake tasks

Skiima Module: sets default for Skiima.root_path location

* uses File.expand_path('.')

Rakefile: added descriptions to gem tasks

Railties tasks: fixes args issues & adds setup task

Spec Helper: updated SKIIMA_ROOT path

Railties tasks: updated descriptions

spec/dependencies.yml: updated with better examples

Railties tasks: reversed order of args

* you're more likely to want to specify the group of scripts to load

* later may change to default env to Rails.env if defined? Rails
Version => 0.3.0

* Readme: updated with better dependencies.yml example