add a test case for cache-control header
add a test case for cache-control header

sdebnath/riak_cs,basho/riak_cs,yangchengjian/riak_cs,dragonfax/riak_cs,GabrielNicolasAvellaneda/riak_cs,GabrielNicolasAvellaneda/riak_cs,laurenrother/riak_cs,yangchengjian/riak_cs,dragonfax/riak_cs,yangchengjian/riak_cs,yangchengjian/riak_cs,laurenrother/riak_cs,laurenrother/riak_cs,sdebnath/riak_cs,sdebnath/riak_cs,basho/riak_cs,basho/riak_cs,dragonfax/riak_cs,sdebnath/riak_cs,laurenrother/riak_cs,dragonfax/riak_cs,basho/riak_cs,GabrielNicolasAvellaneda/riak_cs,GabrielNicolasAvellaneda/riak_cs