updated current_call and forecast_call api calls

[quantumfate]

Fixes #545

• city_id has been refactored to lat and lon

Example usage of the widget

-- Weather
local weathericon = wibox.widget.imagebox(theme.widget_weather)
theme.weather = lain.widget.weather({
    APPID = 'insert api key here',
    lat = '53.55073',
    lon = '9.99302',
    notification_preset = { font = "Noto Sans Mono Medium 10", fg = theme.fg_normal },
    weather_na_markup = markup.fontfg(theme.small_screen_font, "#eca4c4", "N/A "),
    settings = function()
        descr = weather_now["weather"][1]["description"]:lower()
        units = math.floor(weather_now["main"]["temp"])
       widget:set_markup(markup.fontfg(theme.small_screen_font, "#eca4c4", descr .. " @ " .. units .. "°C "))
     end
})

[lcpz]

As this is issue is important and the changes I required were trivial, I implemented them myself.