use ssl for rubygems
use ssl for rubygems

uken/fluent-plugin-elasticsearch,mururu/fluent-plugin-elasticsearch,cosmo0920/fluent-plugin-elasticsearch,jimmidyson/fluent-plugin-elasticsearch,portante/fluent-plugin-elasticsearch,kenatbasis/fluent-plugin-elasticsearch,valdas406/fluent-plugin-elasticsearch,ewolinetz/fluent-plugin-elasticsearch,gtrevg/fluent-plugin-elasticsearch,aerickson/fluent-plugin-elasticsearch,shivaken/fluent-plugin-elasticsearch,ipros-team/fluent-plugin-elasticsearch,ymattw/fluent-plugin-elasticsearch,iwai/fluent-plugin-elasticsearch,njd5475/fluent-plugin-elasticsearch