Config file structure and corresponding code refactoring/optimization

[pavelsr]

I suggest to improve it

• Convert "instructors: {}" to array ("instructors:[]") and remove gmail as unique id
• Replace id on telegram_id for better clearance
• Add service_account section that will indicate gmail account where booking information is stored (good for clearance and easier to app setup). Now it's hardcoded in bot.pl
• Inside of service account and "calendars":[] section . So you will be able to refer a calendar only by its name and don't need to check its ID.
• Ability to automatically fill first_name and last_name from Telegram
• Remove durations and implement it in code

Now minimal config looks like:

{
	"token": "",
	"language": "English",
	"timezone": "Europe/Moscow",
	"workinghours": "08:00-00:00",
	"resources": {
		"Lasersaur": {
			"calendar": "b7qv527m99oqlq3md28cof16jc@group.calendar.google.com"
		}
	},
	"durations": {
		"30_min": 30,
		"1_hour": 60,
		"2_hours": 120,
		"3_hours": 180
	},
	"instructors": {
		"pavel.p.serikov@gmail.com": {
			"id": "218718957", 
			"phone_number": "79885851900",
			"first_name": "Pavel",         
			"last_name": "Serikov"			
		}
	}
}

So it will looks like:

"service_account": {
        "user": "fablab61ru@gmail.com",
        "calendars": [ "Lasersaur", "Dobot", "CTC", "Silhouette"],
       "booking_limit_per_user": 5
    },

"instructors": [
        {
            "first_name": "Pavel",
            "last_name": "Serikov",
            "gmail": "pavel.p.serikov@gmail.com",
            "phone_number": "+79885851900",
            "telegram_id": "@serikoff",
            "calendars": [ "Lasersaur", "Dobot" ]
        },
        {
            "first_name": "Vlad",
            "last_name": "Shvager",
            "gmail": "vlad-shvager@yandex.ru",
            "phone_number": "+79885851900",
            "telegram_id": "@Shvager",
            "calendars": [ "Lasersaur" ]
        }
    ]

AND! It's a good idea to migrate to one config file based on Config::JSON which allow to write in it and is used by my API::Google lib.
It will allow to remove Mojolicious from main bot.pl dependencies so docker image will take less space.