Use ruby 2.1.5 in docker
Use ruby 2.1.5 in docker

- the broker requires this version of ruby.

[#87994366]

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