Fixed incorrect module name in docs/pb-client.txt
Fixed incorrect module name in docs/pb-client.txt

pma/riak-erlang-client,SiftLogic/riak-erlang-client,jmayfield74/riak-erlang-client,linearregression/riak-erlang-client,esl/riak-erlang-client,paulperegud/riak-erlang-client,groovenauts-erlang/riak-erlang-client,GabrielNicolasAvellaneda/riak-erlang-client,rhumbertgz/riak-erlang-client,inaka/riak-erlang-client