Added a possible path of the server to the request execution

There is a possibility of elasticsearch not being in the root path, and there is no way to specify this at the moment. For example, if ES is placed under `localhost:9200/whatever`, and I want to check the cluster state, the request generated by pyes will fail because it will check that in `localhost:9200/_cluster/state` and not in `localhost:9200/whatever/_cluster/state`. This pull request just use the urlparse method, to prepend the original path of the server to the request.