Vitalii/auth service initiation

{
  "typ": "JWT",
  "alg": "RS256",
  "kid": "auth"
}
{
  "bidder_id": "3123636e447c40f3bc53e4ffc127b64c",
  "exp": 1600291145,
  "iss": "prozorro.auth"
}

Auctions auction!326 (merged) Procedures - procedure!996 (merged)