Switch to JSON config

[boxidau]

A JSON config file will allow more flexibility of configuration, config file should look something like this:

{
    "auth": {
        "os_username": "xxxxxxxx",
        "os_password": "93593593573097593579357"
    },
    "autoscale_groups": {
        "group0": {
            "group_id": "3953957397593753975",
            "scale_up_policy": "3975397539759357",
            "scale_down_policy": "3975397539759357",
            "check_type": "agent.load_average",
            "metric_name": "1m",
            "scale_up_threshold": 0.6,
            "scale_down_threshold": 0.4,
            "webhooks": {
                "scale_up": {
                    "pre": [
                        "http://test.com",
                        "http://test123.com"
                    ],
                    "post": [
                        "http://test.com"
                    ]
                },
                "scale_down": {
                    "pre": [
                        "http://test.com",
                        "http://test123.com"
                    ],
                    "post": [
                        "http://test.com"
                    ]
                }
            }
        }
    }
}