add spec for String#scan's output when passed block has multiple arguments
add spec for String#scan's output when passed block has multiple arguments

ruby/rubyspec,ruby/spec,ruby/spec,sgarciac/spec,eregon/rubyspec,nobu/rubyspec,nobu/rubyspec,eregon/rubyspec,sgarciac/spec,ruby/rubyspec,sgarciac/spec,eregon/rubyspec,nobu/rubyspec,ruby/spec