path error when using Show DB Schema for Current Class

[raldred]

command fails whens the rails root is not the TM_PROJECT_DIRECTORY
the show_schema.rb file just assumes the rails root to be the top level directory
This fails when the rails root is a sub directory of the TM_PROJECT_DIRECTORY

project = ENV['TM_PROJECT_DIRECTORY']
word = ENV['TM_CURRENT_WORD']

require "#{project}/config/boot"
require "#{project}/config/environment"

is there a better way the rails root can be found before requiring the environment?