* FIX: remove sinatra gem ( there is an installation error )
 * we might need to check why "gem install" produce error like:

> Mar  4 02:32:34 in-target: unrecognized option `--encoding'
> Mar  4 02:32:34 in-target:
> Mar  4 02:32:34 in-target:
> Mar  4 02:32:34 in-target: For help on options, try 'rdoc --help'
> Mar  4 02:32:34 in-target:
> Mar  4 02:32:34 in-target: ERROR:  While generating documentation for activesupport-3.2.12
> Mar  4 02:32:34 in-target:
> Mar  4 02:32:34 in-target: ... MESSAGE:   exit
> Mar  4 02:32:34 in-target:
> Mar  4 02:32:34 in-target: ... RDOC args: --ri --op /var/lib/gems/1.8/doc/activesupport-3.2.12/ri --encoding UTF-8 lib --title actives
> upport-3.2.12 Documentation --quiet
> Mar  4 02:32:34 in-target:
> Mar  4 02:32:34 in-target: Successfully installed uuidtools-2.1.3
> Mar  4 02:32:34 in-target: Building native extensions.  This could take a while...
> Mar  4 02:32:34 in-target: Successfully installed rake-10.0.3