Add Date#saturday? spec
Add Date#saturday? spec

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