Improve logger to show failed requests URL and when retry will happen

[ArturT]

• Improve logger to show failed requests URL
• More clear message when showing info about waiting for next request retry

Example output:

W, [2020-09-23T13:04:03.675239 #52494]  WARN -- : [knapsack_pro] POST http://api-fake.knapsackpro.test:3000/v1/queues/queue
W, [2020-09-23T13:04:03.675327 #52494]  WARN -- : [knapsack_pro] Request failed due to:
W, [2020-09-23T13:04:03.675354 #52494]  WARN -- : [knapsack_pro] #<SocketError: Failed to open TCP connection to api-fake.knapsackpro.test:3000 (getaddrinfo: nodename nor servname provided, or not known)>
W, [2020-09-23T13:04:03.675392 #52494]  WARN -- : [knapsack_pro] Wait for 8s before retrying the request to Knapsack Pro API.
W, [2020-09-23T13:04:05.678955 #52494]  WARN -- : [knapsack_pro] 6s left before retry...
W, [2020-09-23T13:04:07.683879 #52494]  WARN -- : [knapsack_pro] 4s left before retry...
W, [2020-09-23T13:04:09.689065 #52494]  WARN -- : [knapsack_pro] 2s left before retry...
W, [2020-09-23T13:04:11.697194 #52494]  WARN -- : [knapsack_pro] POST http://api-fake.knapsackpro.test:3000/v1/queues/queue
W, [2020-09-23T13:04:11.697262 #52494]  WARN -- : [knapsack_pro] Request failed due to:
W, [2020-09-23T13:04:11.697296 #52494]  WARN -- : [knapsack_pro] #<SocketError: Failed to open TCP connection to api-fake.knapsackpro.test:3000 (getaddrinfo: nodename nor servname provided, or not known)>
W, [2020-09-23T13:04:11.697338 #52494]  WARN -- : [knapsack_pro] Wait for 16s before retrying the request to Knapsack Pro API.
W, [2020-09-23T13:04:13.701011 #52494]  WARN -- : [knapsack_pro] 14s left before retry...
W, [2020-09-23T13:04:15.706214 #52494]  WARN -- : [knapsack_pro] 12s left before retry...
W, [2020-09-23T13:04:17.711670 #52494]  WARN -- : [knapsack_pro] 10s left before retry...
W, [2020-09-23T13:04:19.714524 #52494]  WARN -- : [knapsack_pro] 8s left before retry...
W, [2020-09-23T13:04:21.716759 #52494]  WARN -- : [knapsack_pro] 6s left before retry...
W, [2020-09-23T13:04:23.718025 #52494]  WARN -- : [knapsack_pro] 4s left before retry...
W, [2020-09-23T13:04:25.722577 #52494]  WARN -- : [knapsack_pro] 2s left before retry...
W, [2020-09-23T13:04:27.735953 #52494]  WARN -- : [knapsack_pro] POST http://api-fake.knapsackpro.test:3000/v1/queues/queue
W, [2020-09-23T13:04:27.736063 #52494]  WARN -- : [knapsack_pro] Request failed due to:
W, [2020-09-23T13:04:27.736125 #52494]  WARN -- : [knapsack_pro] #<SocketError: Failed to open TCP connection to api-fake.knapsackpro.test:3000 (getaddrinfo: nodename nor servname provided, or not known)>