update gemfile to rails 3.1.0.rc1 to bundle properly
update gemfile to rails 3.1.0.rc1 to bundle properly

ayunav/omniauth,omniauth/omniauth,sideci-sample/sideci-sample-omniauth,yui-knk/omniauth,twalpole/omniauth,thomasmillergb/Year2-ruby-software-hut,dougal/omniauth,intridea/omniauth,likeberi/omniauth,thomasmillergb/Year2-ruby-software-hut,poznyakandrey/omniauth,nbrustein/omniauth,mihar/omniauth-timekiwi,ngpestelos/omniauth