Issue #228: Do not allow the creation of an empty RiakObject key
Issue #228: Do not allow the creation of an empty RiakObject key

bmess/riak-python-client,GabrielNicolasAvellaneda/riak-python-client,basho/riak-python-client,bmess/riak-python-client,basho/riak-python-client,GabrielNicolasAvellaneda/riak-python-client,basho/riak-python-client