code: public ConsulResponse<Map<String, List<String>>> getServices(RequestOptions requestOptions) {
          return getServices(null, null, requestOptions);
      }
docs: Retrieves all services for a given datacenter with {@link io.advantageous.consul.domain.option.RequestOptions}.
  <p>
  GET /v1/catalog/services?dc={datacenter}
  
  @param requestOptions The Query Options to use.
  @return A {@link io.advantageous.consul.domain.ConsulResponse} containing a map of service name to list of tags.