Minor Dialyzer fixes and an important fix to the get_option() type.
Minor Dialyzer fixes and an important fix to the get_option() type.

The get_option() type was missing two boolean attributes: the
`notfound_ok` and `basic_quorum` options.

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