Update Rakefile to make Thor happy.
Update Rakefile to make Thor happy.

Thor has already been required. This may cause Bundler to malfunction
in unexpected ways.

futhr/spree-dibs,StemboltHQ/spree-dibs,futhr/spree-dibs,freerunningtech/spree-dibs,StemboltHQ/spree-dibs,freerunningtech/spree-dibs