def log_water(opts)
      unless opts[:amount] && opts[:date]
        raise Fitgem::InvalidArgumentError, "Must include both an :amount and :date to log water"
      end

      opts[:date] = format_date(opts[:date])
      post("/user/#{@user_id}/foods/log/water.json",opts)
    end
def log_water(opts)
      unless opts[:amount] && opts[:date]
        raise Fitgem::InvalidArgumentError, "Must include both an :amount and :date to log water"
      end

      opts[:date] = format_date(opts[:date])
      post("/user/#{@user_id}/foods/log/water.json",opts)
    end
==========================================
          Water Logging Methods
 ==========================================
 Log water consumption to fitbit

 @param [Hash] opts Water consumption data
 @option opts [Integer, Decimal, String] :amount Amount of water
   consumed; if String must be in "X.X" format
 @option opts [String] :unit Unit of water consumed; valid values
   are ("ml", "fl oz" or "cup")
 @option opts [DateTime, Date, String] :date Date of water
   consumption

 @return [Hash] Summary of logged information