A simple bot. Need key from @BotFather.

• Use '/start' to say hello this bot.
• Use '/planet planet_name' to would know in which constellation the planet is now.
• Use '/calculate' or '=' to count.(to do).
• Use '/fullmoon your_date(day-month-year)' to find out when the next full moon(to do).
• Use /remove_keyboard to remove keyboard.