Add support for an attempt to connect to existing Queue on API side to reduce slow requests number

[ArturT]

problem

The very first request to Queue API is slow due to sending a list of test files from the disk. The bigger the test files list the slower is request. For a few thousand test files it can take 1+ second.

When a lot of requests from parallel CI nodes starting at the same time hit the Knapsack Pro API this can lead to slower performance of the API because requests with a list of test files can be slow. This leads to compound effect and degradation of API performance for very large projects using ~100+ parallel CI nodes.

solution

• make attempt to connect to the existing Queue on the API side and don't' send a list of test files from the disk
• if the above attempt failed then send a list of test files from the disk to initialize a new Queue on API side

Thanks to the above we can significantly reduce the number of slow requests and make the overall API more stable.

Related to PR

KnapsackPro/knapsack_pro-ruby#133