Write Enumerable#sum specs
Write Enumerable#sum specs

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