r3 app tpl - use edge rails

app_template__use_edge_rails.rb

# usage (in app dir): 
# rake rails:template LOCATION=http://gist.github.com/403207.txt 

### Append edge rails lines to end of Gemfile

# get existing file
gemfile_contents = File.readlines 'Gemfile'

# uncomment edge rails statement (line #6)
gemfile_contents[5].sub!('#', '').lstrip!

# overwrite existing file
File.open('Gemfile', 'w') do |gemfile_out|
gemfile_out.write(gemfile_contents.join)
end

# refresh rails version
run "bundle install"