Fixed join_cluster script so that it actually ends.
Fixed join_cluster script so that it actually ends.

mikfreedman/cf-riak-cs-release,cloudfoundry/cf-riak-cs-release,datianshi/cf-riak-cs-release,mikfreedman/cf-riak-cs-release,cloudfoundry/cf-riak-cs-release,datianshi/cf-riak-cs-release,datianshi/cf-riak-cs-release,datianshi/cf-riak-cs-release,cloudfoundry/cf-riak-cs-release,mikfreedman/cf-riak-cs-release,mikfreedman/cf-riak-cs-release,cloudfoundry/cf-riak-cs-release