code: function (deviceIdentifier, identifierUrn) {
        var path;
        if (deviceIdentifier && identifierUrn) {
          path = this.constructPath(constants.DEVICES, deviceIdentifier, constants.IDENTIFIERS, identifierUrn);
          return this.Core.DELETE(path);
        } else {
          return this.rejectRequest('Bad Request: A device identifier and an identifier id are required.');
        }
      }
docs: Delete an identifier from a device
  @param  {String|Integer} deviceIdentifier A Robin device identifier
  @param  {String|Integer} identifierUrn    A Robin identifier URN
  @return {Function}                        A Promise