Add first pass at `riak_cs_utils:valid_bucket_name/1` tests
Add first pass at `riak_cs_utils:valid_bucket_name/1` tests

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