Bidmatic Bid Adapter: update API

[GeneGenie]

Type of change

• Updated bidder adapter

Description of change

• Updated adapter api.
• Added new ENV props.
• No bidder params changed.

var adUnits = [{
    code: 'bg-test-rectangle',    
    sizes: [[300, 250]],     
    bids: [{
        bidder: 'bidmatic',
        params: {
            source: 886409,
        }
    }]
}]