add dump file to gitignore
add dump file to gitignore

RailsGEnthusiasts/RubyGameDev.com,ruby-rcade/RubyGameDev.com,PowerCodeGirls/RubyGameDev.com,PowerCodeGirls/RubyGameDev.com,RailsGEnthusiasts/RubyGameDev.com,ruby-rcade/RubyGameDev.com,RailsGEnthusiasts/RubyGameDev.com,PowerCodeGirls/RubyGameDev.com,ruby-rcade/RubyGameDev.com