added get settings API call
added get settings API call

Closes #721

trandangtri/ElasticsearchBundle,tautrimas/ElasticsearchBundle,martiis/ElasticsearchBundle,asev/ElasticsearchBundle,tautrimas/ElasticsearchBundle,saimaz/ElasticsearchBundle,martiis/ElasticsearchBundle,ongr-io/ElasticsearchBundle,murnieza/ElasticsearchBundle,asev/ElasticsearchBundle,trandangtri/ElasticsearchBundle,saimaz/ElasticsearchBundle,murnieza/ElasticsearchBundle