remove travis env setting
remove travis env setting

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